UCSD Physics News

Migratory birds often use warm, rising atmospheric currents to gain height with little energy expenditure when flying over long distances.

news picture It's a behavior known as thermal soaring that requires complex decision-making within the turbulent environment of a rising column of warm air from the sun baked surface of the earth. But exactly how birds navigate within this ever-changing environment to optimize their thermal soaring was unknown until a team of physicists and biologists at the University of California San Diego took an exacting computational look at the problem.

In this week's online version of the journal Proceedings of the National Academy of Sciences, the scientists demonstrated with mathematical models how glider pilots might be able to soar more efficiently by adopting the learning strategies that birds use to navigate their way through thermals.

"Relatively little is known about the navigation strategies used by birds to cope with these challenging conditions, mainly because past computational research examined soaring in unrealistically simplified situations," explained Massimo Vergassola, a professor of physics at UC San Diego.

To tackle the problem, he and his colleagues, including Terrence Sejnowski, a professor of neurobiology at the Salk Institute and UC San Diego, combined numerical simulations of atmospheric flow with "reinforcement learning algorithms"-equations originally developed to model the behavior and improved performance of animals learning a new task. Those algorithms were developed in a manner that trained a glider to navigate complex turbulent environments based on feedback on the glider's soaring performance.

According to Sejnowski, the "reinforcement learning architecture" was the same as that used by Google's DeepMind AlphaGo program, which made headlines in 2016 after beating the human professional Go player Lee Sedol.

When applying it to soaring performance, the researchers took into account the bank angle and the angle of attack of the glider's wings as well as how the temperature variations within the thermal impacted vertical velocity.

"By sensing two environmental cues-vertical wind acceleration and torque-the glider is able to climb and stay within the thermal core, where the lift is typically the largest, resulting in improved soaring performance, even in the presence of strong turbulent fluctuations," said Vergassola. "As turbulent levels rise, the glider can avoid losing height by adopting increasingly conservative, risk-averse flight strategies, such as continuing along the same path rather than turning."

The researchers write in their paper that, based on their study, "torque and vertical accelerations" appear to be the sensorimotor cues that most effectively guide the most efficient soaring path of birds through thermals, rather than differences in temperature.

"Temperature was specifically shown to yield minor gains," they write adding that "a sensor of temperature could then be safely spared in the instrumentation for autonomous flying vehicles."

"Our findings shed light on the decision-making processes that birds might use to successfully navigate thermals in turbulent environments," said Vergassola. "This information could guide the design of simple mechanical instrumentation that would allow autonomous gliders to travel long distances with minimal energy consumption."

"The high levels of soaring performance demonstrated in simulated turbulence could lead to the development of energy efficient autonomous gliders," said Sejnowski, who is also a Howard Hughes Medical Institute Investigator.

Other members of the research team were Gautam Reddy, a physicist at UC San Diego and the first author of the paper, and Antonio Celani of the Abdus Salam International Center for Theoretical Physics in Trieste, Italy. The study was supported by a grant from the Simons Foundation.

Last modified: 08/23/2016

X-Ray Snapshot of Butterfly Wings Reveals Underlying Physics of Color

news picture A team of physicists that visualized the internal nanostructure of an intact butterfly wing has discovered two physical attributes that make those structures so bright and colorful.

"Over millions of years, butterflies have evolved sophisticated cellular mechanisms to grow brightly colored structures, normally for the purpose of camouflage as well as mating," says Oleg Shpyrko, an associate professor of physics at UC San Diego, who headed the research effort. "It's been known for a century that the wings of these beautiful creatures contain what are called photonic crystals, which can reflect light of only a particular color."

But exactly how these complex optical structures are assembled in a way that make them so bright and colorful remained a mystery.

In an effort to answer that question, Shpyrko and Andrej Singer, a postdoctoral researcher in his laboratory, went to the Advanced Photon Source at the Argonne National Laboratory in Illinois, which produces coherent x-rays very much like an optical laser

By combining these laser-like x-rays with an advanced imaging technique called "ptychography," the UC San Diego physicists, in collaboration with physicists at Yale University and the Argonne National Laboratory, developed a new microscopy method to visualize the internal nanostructure of the tiny "scales" that make up the butterfly wing without the need to cut them apart.

The researchers report in the current issue of the journal Science Advances that their examination of the scales of the Emperor of India butterfly, Teinopalpus imperialis, revealed that these tiny wing structures consist of "highly oriented" photonic crystals.

"This explains why the scales appear to have a single color," says Singer, the first author of the paper. "We also found through careful study of the high-resolution micrographs tiny crystal irregularities that may enhance light-scattering properties, making the butterfly wings appear brighter."

These crystal dislocations or defects occur, the researchers say, when an otherwise perfectly periodic crystal lattice slips by one row of atoms. "Defects may have a negative connotation, but they are actually very useful in improving materials," explains Singer. "For example, blacksmiths have learned over centuries how to purposefully induce defects into metals to make them stronger. 'Defect engineering' is also a focus for many research teams and companies working in the semiconductor field. In photonic crystals, defects can enhance light-scattering properties through an effect called light localization."

"In the evolution of butterfly wings," he adds, "it appears nature learned how to engineer these defects on purpose."

Other scientists involved in the study include Leandra Boucheron and Sebastian Dietze of UC San Diego, David Vine and Ian McNulty of Argonne National Laboratory, and Katharine Jensen, Eric R. Dufresne, Richard Prum and Simon Mochrie of Yale. The research project was supported by grants from the U.S. Department of Energy's Office of Science and Office of Basic Energy Sciences.

Further Story at: http://www.sandiegouniontribune.com Story Attribution: Kim McDonald

Last modified: 06/13/2016

New $40 Million Observatory to Probe First Moments of Universe

news picture Physicists understand fairly well what happened after the Big Bang and the laws of physics that govern the universe. It's what the universe looked like immediately after the event-a trillionth of a trillionth of a trillionth of a second after-that is still a mystery. A new observatory in Chile's Atacama Desert could be the key to understanding that instance. Called the Simons Observatory, it is being funded by grants totaling $40 million from the Simons Foundation and the Heising-Simons Foundation and will involve a consortium of researchers, including astrophysicists from UC San Diego. "This is an ambitious project with the potential to greatly expand our understanding of the universe, and it wouldn't be possible without private support," said UC San Diego Chancellor Pradeep K. Khosla. "We are deeply grateful to the Simons Foundation and the Heising-Simons Foundation for their partnership. Philanthropy is increasingly important to fuel basic science research and pursue high-risk, high-reward experiments."

How does one study the beginnings of the universe? A primary objective of the project is to search more than half the sky for the signature of the gravitational waves generated immediately following the Big Bang.

Building on two existing facilities, the Atacama Cosmology Telescope and the Simons Array, the funding will support the development and deployment of new technologies to explore the cosmic microwave background (CMB), a window to the physics of the earliest universe. The cosmic microwave background is essentially remnant radiation from the Big Bang that has cooled and stretched with the expansion of the universe to microwave lengths. It acts as an enormous backlight, illuminating the large-scale structure of the universe and carrying an imprint of cosmic history.

Gravitational waves are ripples in the fabric of space-time, first predicted by Albert Einstein as part of his theory of general relativity. During inflation, the rapid expansion of space following the Big Bang (and the leading theory about the beginning of the universe), gravitational waves induced faint, but characteristic polarization patterns in the CMB, at radio wavelengths that can be detected by specialized telescopes and cameras.

Detecting these ancient signals is considered the "holy grail" of cosmology. It would have profound impacts for not only understanding how the universe was formed, but also the fundamental physics that govern it.

"We have this beautiful edifice of everything that's happened in the universe and the laws of physics since about a second after the Big Bang," said Brian Keating, a professor of physics at UC San Diego's Center for Astrophysics and Space Sciences and the current director of the Simons Observatory. "But we want to go back orders of magnitude-perhaps as many as 30 orders of magnitude farther back in time or higher in temperature. We're trying to understand the nature of matter and energy and understand the first moments of the universe, potentially what brought it into existence."

The Simons Observatory will also be used to study dark matter and dark energy, two of the most mysterious substances known to science, but which make up about 96 percent of the universe's total matter and energy.

The search for gravitational waves is not new. Einstein first predicted their existence in 1916; in the 1960s and 70s, advances in technology enabled scientists to attempt to detect these ripples in space-time. However, it's only in the last decade or so that the search has really taken off. Just this year, researchers at the Laser Interferometer Gravitational-Wave Observatory (LIGO) announced they had detected the existence of gravitational waves-a "whisper" heard as two black holes collided. The announcement marked a significant achievement for astrophysicists and a positive sign for Keating and his team, who are not looking for just any gravitational waves; they're searching for signals from those generated in moments after the Big Bang.

Located in Chile's Atacama Desert, the Simons Observatory will bring together leading researchers from UC San Diego; University of Pennsylvania; University of California, Berkeley; Princeton University; Lawrence Berkeley National Laboratory; and University of Wisconsin at Madison, and will provide funding to develop and deploy new telescopes and technologies. The participating institutions are also contributing financial support to the project.

"People are used to thinking about mega- or giga-pixel detectors in optical telescopes, but for signals in the microwave range 10,000 pixels is a lot," said Keating. "What we're trying to do- the real revolution here-is to pave the way to increase our pixels number by more than an order of magnitude."

Keating and his colleagues believe that this investment in new infrastructure and scientific collaboration will position the observatory to significantly advance the search for primordial gravitational waves.

"This new observatory follows the great tradition of astrophysical discovery at UC San Diego and will enable astronomers to have a world-class instrument for decades to come," added Mark Thiemens, dean of UC San Diego's Division of Physical Sciences.

The Simons Foundation is a longtime supporter of UC San Diego's efforts to understand the early universe. Co-founded in New York City by Jim and Marilyn Simons, the foundation's mission is to advance the frontiers of research in mathematics and the basic sciences. In addition to this latest grant, the foundation helped fund the original three-telescope Simons Array at UC San Diego's James Ax Observatory in 2012.

For Keating, the Simons Observatory represents an opportunity to answer an age-old quest to understand the place that humans have in the universe, and to understand the origins of time and space.

"I've always been interested in answering the biggest questions, and this is the biggest question of all," said Keating. "The very first Neanderthals must have looked up and wondered, 'Where did everything come from?' We're finally able to start to answer those questions."

Story Attribution: KRISTIN LUCIANI

Last modified: 05/12/2016

Astronomers Discover Three Potentially Habitable Earth-Sized Worlds Around A Dim Star 40 Light-years Away

news picture An international team of astronomers, including UC San Diego's Professor Adam Burgasser and graduate student Daniella Bardalez Gagliuffi, has reported in Nature the discovery of three Earth-sized planets orbiting near the "habitable zone" of an ultracool dwarf star named TRAPPIST-1, 40 light years in the direction of the constellation Aquarius. These are the first terrestrial planets to be discovered around such a tiny and dim star, and opens a new avenue in the search for life beyond Earth.

The planets were found via the transit method, in which a planet passing between us and its host star blocks a small portion of the starlight, producing a subtle but periodic dimming pattern. Multiple transits for this star were detected with the TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) telescope, and their timings indicate the presence of three planets with orbit periods between 1.5 days and 73 days. These short orbits are likely to be in or around the habitable zone of the star, a zone in which liquid water could potentially exist on the planets' surfaces. Evidence that this is the case will have to wait until the 2018 launch of the James Webb Space Telescope, which will have the capability of measuring the chemical composition of these planets' atmospheres.

Last modified: 05/02/2016

Yusuke Kosuga (PhD 2012) wins Young Scientist Award of the Physical Society of Japan

news picture Congratulations to Yusuke Kosuga (PhD 2012) for winning the 10th Young Scientist Award of the Physical Society of Japan (Division 2,Plasma Physics).Kosuga,who is currently Assistant Professor in The Institute for Advanced Study and Research Institute of Applied Mechanics of Kyushu University,was cited for:

"Research on plasma turbulence and transport with statistical fluctuation in real and velocity space"

The full announcement in English may be found at:

and in Japanese and English at : http://www.jps.or.jp/english/file/10th_wakate2016.pdf.

Work done at UCSD,the WCI Center for Fusion Theory (RoK),and Kyushu University was listed in the full citation. At UCSD,Kosuga was a member of the Diamond group in CASS and and Physics.

Last modified: 04/07/2016

Adam Burgasser: 2015/16 Distinguished Teaching Award for Academic Senate Members

news picture Prof. Adam Burgasser has been selected by the Committee on Senate Awards as a recipient of the 2015/16 Distinguished Teaching Award for Academic Senate Members.

The Distinguished Teaching Award is a prestigious award bestowed upon up to five members of the Academic Senate, three non-Senate faculty members, and three graduate students at UC San Diego each year. The Distinguished Teaching Award was created because UC San Diego faculty recognize the important role excellent teaching plays at the University. This Award is a tangible expression of UC San Diego's commitment to excellence in teaching and to ensuring that this commitment is maintained. The Committee on Distinguished Teaching seeks to select those who exhibit creativity, innovative teaching methods, the ability to motivate students to actively seek out knowledge, and an extraordinary level of teaching commitment.

Last modified: 03/22/2016

Eric Michelsen: 2015/16 Barbara and Paul Saltman Distinguished Teaching Award

news picture Dr. Eric Michelsen has been selected by the Committee on Senate Awards as a recipient of the 2015/16 Barbara and Paul Saltman Distinguished Teaching Award for Non-Senate Members.

The Distinguished Teaching Award is a prestigious award bestowed upon up to five members of the Academic Senate, three non-Senate faculty members, and three graduate students at UC San Diego each year. The Distinguished Teaching Award was created because UC San Diego faculty recognize the important role excellent teaching plays at the University. This Award is a tangible expression of UC San Diego's commitment to excellence in teaching and to ensuring that this commitment is maintained. The Committee on Distinguished Teaching seeks to select those who exhibit creativity, innovative teaching methods, the ability to motivate students to actively seek out knowledge, and an extraordinary level of teaching commitment.

In 1999-2000, the establishment of an endowment in memory of Professor Paul D. Saltman extended the Distinguished Teaching Awards to non-Senate faculty members and graduate students who meet the award criteria and who also exhibit other qualities that emulate Professor Saltman's passion for teaching and learning.

Last modified: 03/22/2016

UC San Diego Biophysicists Discover How Hydra Opens Its Mouth

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A team of biologists and physicists at UC San Diego has uncovered in detail the dynamic process that allows the multi-tentacle Hydra, a tiny freshwater animal distantly related to the sea anemone, to open and close its mouth.

The researchers report their findings in the current issue of Biophysical Journal. They say their discovery not only solves a long-standing puzzle of how Hydra feeds, but also enabled them to address a complex phenomenon in a living animal using relatively simple physics.

"The reasons why this work is exciting is that there are very few systems in which you can do quantitative measurements in vivo," said Eva-Maria S. Collins, an assistant professor of biology and physics at UC San Diego who headed the research team. "Hydra is such a simple organism; it allows us to perform controlled perturbations and quantitative measurements in the natural context."

The de velopment of transgenic Hydra several years ago by Robert Steele of UC Irvine, however, has enabled biologists for the first time to track individual cells within the freshwater animal. Steele, who is a co-author of the paper, provided transgenic Hydra with green fluorescent and red fluorescent proteins tagged to cytoplasmic proteins in its ectodermal and endodermal epithelial cells, respectively. This allowed the team of researchers, which included UC San Diego biology master's student Jason Carter and postdoctoral fellow Callen Hyland, to observe the cellular dynamics of the opening of the Hydra's mouth for the first time.

Because mouth opening involves major morphological changes, other biologists had suggested that in order to open its mouth, Hydra had to "rearrange" the positions of the cells between its tentacles to create and then expand the opening. But through live imaging, the UC San Diego scientists discovered that the process by which Hydra opened its mouth fully occurred on fairly fast time scales, on the order of 60 seconds.

"It's fascinating that Hydra has to tear a hole every time it opens its mouth," said Collins. "And that this process happens so quick; this was the first indication to us that mouth opening did not involve cellular rearrangements."

By tracking the position of the tagged cells and analyzing the changes in position, the researchers confirmed that the process did not involve rearrangement of cells. Instead, using shape analysis, they discovered that mouth opening was achieved through dramatic elastic deformations of the cells surrounding the mouth.

The driving force responsible for mouth opening are radially oriented contractile elements called "myonemes" in the animal's ectodermal cells, which basically act like muscles. This was confirmed experimentally by using magnesium chloride, a muscle relaxant, which prevented the mouth from opening.

The scientists also found in their experiments that individual Hydra were able to open their mouths consecutively by different amounts, varying up to an order in magnitude in final opening area. However, by scaling each opening curve by its maximum opening, they found that the relative rate of opening was conserved, suggesting that the degree to which the mouth opens is controlled by nerve signaling.

Collins said that because Hydra is such a simple animal and because it is able to regenerate after complete dissociation into individual cells, it offers researchers the opportunity to use similar techniques as the ones employed in their experiments to examine how an organism develops from an unstructured group of cells into a complex body plan.

"We can now use this system to examine more closely two processes that are fundamental to all organisms: tissue formation and patterning," she said.

Story Attribution: Kim McDonald

Last modified: 03/11/2016

New material can control excitons at room temperature

news picture A team of physicists from the University of California, San Diego and The University of Manchester is creating tailor-made materials for cutting-edge research and perhaps a new generation of optoelectronic devices. The materials make it easier for the researchers to manipulate excitons, which are pairs of an electron and an electron hole bound to each other by an electrostatic force.

Excitons are created when a laser is shone onto a semiconductor device. They can transport energy without transporting net electric charge. Inside the device the excitons interact with each other and their surroundings, and then convert back into light. This makes them attractive for new technology. Inside the device the excitons interact with each other and their surroundings, and then convert back into light that can be detected by extremely sensitive charge-coupled device (CCD) cameras.

Most of the team's previous work involved structures based on gallium arsenide (GaAs), which is a material commonly used throughout the semiconductor industry. Unfortunately, the devices they've developed come with a fundamental limitation: They require cryogenic temperatures (below 100 K)-ruling out any commercial applications.

So the team made a radical material change to bring their excitonic devices up to room temperature. They report their results in Applied Physics Letters.

"Our previous structures were built from thin layers of GaAs deposited on top of a substrate with a particular layer thickness and sequence to ensure the specific properties we wanted," said Erica Calman, lead author and a graduate student in the Department of Physics, University of California, San Diego.

To make the new devices the physicists turned to new structures built from a specially designed set of ultrathin layers of materials-molybdenum disulfide (MoS2) and hexagonal boron nitride (hBN)-each a single atom thick.

These structures are produced via the famous "Scotch tape" or mechanical exfoliation method developed by the group of Andre Geim, a physicist awarded a Nobel Prize in physics in 2010 for his groundbreaking work regarding the two-dimensional material graphene.

"Our specially designed structures help keep excitons bound more tightly together so that they can survive at room temperature-where GaAs excitons are torn apart," explains Calman.

Impressively, excitons can form a special quantum state known as a Bose-Einstein condensate. This state occurs within superfluids and enables currents of particles without losses. The team discovered a similar exciton phenomenon at cold temperatures with GaAs materials.

"The results of our work suggest that we may be able to make new structures work all the way up to room temperature," said Calman. "We set out to prove that we could control the emission of neutral and charged excitations by voltage, temperature, and laser power ... and demonstrated just that."

Last modified: 03/11/2016

Professor Julio Barreiro named 2016 Sloan Fellow.

news picture Alfred P. Sloan Foundation has named Prof. Julio Barreiro as 2016 Sloan Fellow. He is one of 126 talented young U.S. and Canadian researchers to receive this distinction.

The Sloan Research Fellowships seek to stimulate fundamental research by early-career scientists and scholars of outstanding promise. These two-year fellowships are awarded yearly to 126 researchers in recognition of distinguished performance and a unique potential to make substantial contributions to their field. Read more about this at:


Last modified: 02/26/2016

Professors Eva-Maria S. Collins and Dusan Keres named 2016 Cottrell Scholars

news picture The Research Corporation for Science Advancement (RCSA) has named Prof. Eva-Maria S. Collins and Prof. Dusan Keres as 2016 Cottrell Scholars. They are part of a very select group of 24 early career academic scientists to receive this distinction.

Read more about this award at http://rescorp.org/news/2016/02/rcsa-names-24-cottrell-scholars-for-2016-funds-2.4m-in-research-science-edu

Last modified: 02/26/2016

Jeremie Palacci, assistant professor of physics, receives NSF Career Award

news picture Jeremie Palacci, assistant professor of physics, has received an NSF Career Award to pursue research on emergent properties in synthetic active matter including self-organization and synchronization.

More about Emergent Properties

Last modified: 02/23/2016

Andrew Ulvestad (Shpyrko group) discovers Molecular "Avalanches" in hydrogen storage materials

news picture Imagine a sponge that could soak up a thousand times its own volume in water. Now imagine how effective that sponge would be if it could store hydrogen instead of water, giving researchers an alternative to compressed air cylinders for storing the gas.

Palladium, a precious metal closely related to platinum, is that sponge. Unlike any other element, it takes up hydrogen at room temperature and pressure. In a recent study, Andrew Ulvestad (Physics PhD student in Shpyrko group) and co-workers have gained new insight into how this uptake of hydrogen occurs, realized how it impacts the atomic structure of the palladium, and identified key properties of how this form of hydrogen storage could work in the future.

When hydrogen is cycled into the palladium nanoparticles, it alters and degrades the particles' structure over time due to strain. "It's like trying to put your foot in too small of a shoe," said Dr. Andrew Ulvestad (recent UCSD Physics PhD in Shpyrko group, and currently a Directoral Postdoctoral Fellow at Argonne), who was the study's first author.

See: A. Ulvestad, M.J. Welland, S.S.E. Collins, R. Harder, E. Maxey, J. Wingert, A. Singer, S. Hy, P. Mulvaney, P. Zapol, O.G. Shpyrko, "Avalanching strain dynamics during the hydriding phase transformation in individual palladium nanoparticles," Nat. Commun. 6, 10092-1 (2015). DOI: 10.1038/ncomms10092 (Link: http://www.nature.com/ncomms/2015/151211/ncomms10092/abs/ncomms10092.html)

Last modified: 02/01/2016

Star Role Models

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As the number of women interested in majoring in physics increases, three new physics professors hope to open doors for those seeking to pursue research careers.

Quinn Konopacky measures the infrared radiation emanating from Jupiter-sized planets outside of our solar system, which provides a view of their distant atmospheres.

Shelley Wright is leading a search for laser pulses from intelligent life in the universe while developing a crucial instrument that will allow astronomers to see distant stars more clearly on what will become the world's largest telescope.

And Karin Sandstrom is studying the diffuse gas and dust between the stars in galaxies, tracking how it evolves over the history of the universe.

These three women- astrophysicists recently hired as assistant professors of physics in UC San Diego's Division of Physical Sciences and the Center for Astrophysics and Space Sciences, or CASS-are giving humanity a view of the universe as it's never been seen before.

But their impact goes far beyond their pioneering celestial research on telescopes around the world. On campus, they've joined UC San Diego's four other female physics professors-Alison Coil, Eva-Maria Collins, Olga Dudko and Elizabeth Jenkins-as important mentors and role models for women like themselves hoping to pursue careers in astronomy and physics.

"Astronomy and physics are still very male-dominated fields, and it can be challenging for women to get to the next level," explained Konopacky. "So even though record numbers of women are entering graduate school in these fields, it's still difficult to push through to the next level and get permanent positons. What we used as our role models were the women who were able to survive during much more difficult and much more challenging times; people like my former graduate advisor at UCLA, Andrea Ghez, or Margaret Burbidge, who is a distinguished emeritus physics professor here, or Sally Ride [a former physics professor at UC San Diego]. I hope that through my teaching and by involving students in my research I can help open up more doors for women in the future who are following behind me as well."

"Improving diversity in any field benefits the community as a whole," said Wright, noting that she's honored to be on the same campus where Maria Mayer, the second woman ever to win a Nobel Prize, was hired as a physics professor, and Margaret Burbidge, who was initially denied access to Palomar Observatory because of her gender, paved the way for the current generation of women astronomers. "We're scientists and, as scientists, we know that when you bring in people with different perspectives and experiences, it helps you solve problems."

Recognizing those benefits, more and more of the nation's universities are making diversity a top priority in faculty recruitments. But that trend has also heightened competition among the top research institutions for the best candidates. All of which makes UC San Diego's recruitment of three prominent female early-career astrophysicists a remarkable achievement.

"This was a coup," said George Fuller, the director of CASS, adding that astronomy and physics departments around the country have taken notice and many have sent congratulations. "These are outstanding scientists. And they are working in fields that are very crucial to us."

During the 2014 academic year, about one-third of the nation's physics and astronomy departments hired exclusively men, said Susan White, a statistician at the American Institute of Physics, in College Park, Md., who keeps track of annual hiring statistics for astronomy and physics at U.S. universities and colleges. Among the remaining two-thirds of institutions that were successful in adding a female physics or astronomy faculty member, "the vast majority hired one woman, while about 10 percent hired two," she said.

"I would say it's very exceptional," added White of the campus' three new physics faculty recruitments. "That's very hard to do."

U.C. San Diego's physics department is not alone in making substantial strides in improving the diversity of its physical science faculty. Last June, Chemical & Engineering News ranked UC San Diego's chemistry and biochemistry department second in the nation in a survey of professorships held by underrepresented minorities.

"Our ability to recruit the best early-career scientists is a testament to the strength of our faculty and research programs," said Mark Thiemens, dean of the Division of Physical Sciences. But it's also been helped along by an innovative hiring program in the division to increase faculty diversity in physics, chemistry and mathematics-disciplines long dominated by white males.

"We told the departments to search for anyone, in any field," he added. "Above all, they must be an extraordinary scholar, but one with an exceptional commitment to diversity. Standard searches aren't sufficient to move the needle. You have to be aggressive, to go out and find the best people."

While the physics department last year was provided funding from the campus to hire one new faculty member, the exceptional background of the three candidates allowed it to argue for a second position through the division's excellence fund and a third from the UC Office of the President, said Ben Grinstein, chair of the physics department.

So what will be the impact for students of the near doubling in one year of the number of female physics professors on campus? Plenty.

Grinstein pointed out that the number of female physics majors on the campus has steadily grown, nearly tripling in just the past eight years-from 36 students in 2008 to 101 students in the 2015 fall quarter. That trend, he said, underlines the importance of having visible role models and mentors among the faculty for women hoping to pursue advanced degrees and careers in physics and astronomy.

According to the American Institute of Physics, female graduate students and postdocs in those fields are frequently hampered by "the imposter syndrome"-the belief that they don't really belong in scientific disciplines dominated by men. As a consequence, many women drop out before they can establish their careers as scientists. But effective mentors, particularly other women scientists, have been shown in studies to counteract that problem.

"Men can also be exceptional mentors," said White. "But there's something about being someone who looks like you. It's easier to believe you can do something when they look like you."

Along with Alison Coil, an associate professor of physics who has long taken the leadership on campus in promoting opportunities for women in astronomy and physics, the three new assistant professors have been working with students to help plan a three-day regional Conference for Undergraduate Women in Physics, which took place on the campus last weekend.

Sandstrom is mentoring an undergraduate physics major, Bethany Ludwig, on a project studying the dust from a supernova remnant and is overseeing the work of a graduate student from Bulgaria, Petia Yanchulova Merica-Jones, examining the glowing dust from images taken by the Hubble Space Telescope. Konopacky is working with Debbie Tran, a physics major specializing in astrophysics, who has been helping her analyze data from the Gemini Planet Imager, the instrument in Chile and Hawaii from which they are able to obtain detailed information in the infrared about the atmospheres of Jupiter-like planets outside of our solar system.

"Debbie has made a huge amount of progress in a very short time and the work that she's done has already been incorporated into papers by a number of different people in our collaboration," said Konopacky.

Fuller said he hopes the increased interest in physics and astronomy among women on the campus-and the corresponding increase in women faculty mentors this year-will translate into more females entering careers in physics and astronomy because the opportunities for research have expanded.

"New areas in astrophysics have been created that didn't exist a few years ago," he said. "If you throw away half the population, you're not doing the field or your institution any good."

Fuller noted that the physics faculty takes special pride in the fact that UC San Diego was one of the first universities to actively recruit the best women physicists and astronomers in the world-at a time when other universities wouldn't hire them as full-time faculty members or would otherwise put restrictions on their employment.

"UC San Diego was a pioneer in that regard," he said. Before Maria and Joseph Mayer were recruited to the campus in 1960 from the University of Chicago, for example, it was Joseph, not Maria, who had a faculty position. "Maria only had a desk there," Fuller said. "UC San Diego gave Maria Mayer her first faculty job." In 1963, as a professor of physics here, Mayer won the Nobel Prize in Physics for proposing the nuclear shell model of the atomic nucleus.

Two years after Maria Mayer's arrival, in 1962, Margaret Burbidge and her husband Geoffrey were recruited from the University of Chicago as professors. But in order to avoid the anti-nepotism hiring rules at the time, the campus found a way to hire Margaret as a chemistry professor because Geoffrey's appointment was in physics. Margaret was eventually given a professorship in physics, served as the first director of CASS from 1979 to 1988 and was awarded the National Medal of Science in 1983.

The late Sally Ride, the first American woman in space, was appointed a professor of physics in 1989 on the campus as well as director of the California Space Institute. She was an emeritus professor of physics at UC San Diego until her death in 2012.

In recent decades, Fuller lamented that the university hadn't been able to build on its longstanding tradition of breaking the glass ceiling for outstanding women physicists by providing more faculty positions to women. But he's clearly thrilled that in one year, in one fell swoop, the pendulum has swung back again.

"We're a world leader again," said Fuller proudly.

Author: Kim McDonald

Last modified: 01/26/2016

Campus Conference Welcomes Undergraduate Women in Physics

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At a time when women remain underrepresented in the sciences and a student can still complete a physics degree without taking a class in her major led by a female professor, UC San Diego welcomed nearly 200 students to a conference for undergraduate women in physics this past weekend.

"We wanted to provide an opportunity to make connections," said Emily Payne, a fourth-year physics major who led the local organizing committee. "What I mean by that is not so much networking to find jobs, but to create a community."

Young women enroll in high school physics classes in numbers equal to men, but earn only 20 percent of bachelor's degrees in physics, according to the American Institute of Physics Statistical Research Center. This leaking pipeline has delivered too few women to the top reaches of science professions where they represent just 8 percent of senior physics faculty.

The conference countered the experience of being outnumbered with a weekend of events featuring women in physics at all stages of a variety of careers. They shared their research, heard talks and discussed posters, engaged in workshops, visited labs and participated in panel discussions. NASA's flight director for the International Space Station, Ginger Kerrick, gave the keynote address.

Payne and her colleagues, a band of young women majoring in physics here, hope the experiences they planned will encourage women to stay in the field. "We want to create a sense of belonging," Payne said. "They do belong. There's a place for them."

The conference is part of a national program run by the American Physical Society. UC San Diego's meeting drew participants from schools throughout the southwestern U.S. and Hawaii, from big research universities to small community colleges.

To keep barriers to participation low, registration cost just $25, hotel fees were covered and participants whose home departments were unable to provide travel funds will have their expenses reimbursed.

Pulling that off was a learning experience for the young organizers, said physics professor Adam Burgasser who along with his colleagues Quinn Konopacky and Karin Sandstrom advised the group. "They now have the experience of asking for resources for things they want to accomplish. That's a really key skill to develop."

They also have the experience of arranging two full days of events. "It's a huge thing to organize, and they succeeded. Now they'll be more confident when they do it again," Burgasser said.

Activities included workshops on writing skills and creating a professional presence on social media, how to get into graduate school, become involved in research as an undergraduate, deal with imposter syndrome and find jobs with a bachelor's degree in physics.

Several physics laboratories at UC San Diego hosted visits to show how they study interactions of matter with antimatter, quantum-based materials, and origins of the universe. A tour of General Atomics and a panel discussion on working in industry offered perspectives beyond the university.

Participants also explored future pathways during a career fair and a panel discussion on issues faced by women who pursue careers in STEM field. That panel included physics alumna Elisa Quintana '97, a scientist at NASA Ames Research Center who led the discovery of the first Earth-like planet within the habitable zone of another star, but said she received backlash from some senior men in her field.

In a welcoming address Friday evening, physics professor Alison Coil pointed out that most people hit bumps along the way and shared a few of her own-from cloudy nights that obscured her view of the galaxies she studies to the absence of her graduate advisor during a long medical leave.

"It helps to be tenacious," Coil advised. "Find some perseverance in yourself and don't be derailed. If you have a competitive spark within you, become friends with it. It'll help you." She also emphasized the importance of finding peers to meet with and discuss experiences.

Coil shared what she loves about being a professor and an astrophysicist, and encouraged the students to pursue sometimes difficult paths that might lead to their own professional rewards. "You should challenge yourselves," she said, "because you're stronger than you know."

Author: Susan Brown

Last modified: 01/26/2016

Researchers Unravel Age-Old Mystery of Why Cells Use Fermentation

news picture Wine, beer and yogurt are produced when microorganisms convert sugar into alcohol, gases or acids. But this process of fermentation-which is used by bacteria, fungi and other fast-growing cells to generate energy in the absence of oxygen-is a much less efficient way of generating energy for cells than aerobic respiration.

So why do many organisms use this seemingly wasteful strategy to generate energy instead of aerobic respiration, even when oxygen is readily available?

Biologists have pondered this conundrum for nearly a century and dubbed it the "Warburg effect" after the Nobel-Prize winning cell biologist Otto Warburg. He discovered in the 1920s that cancer cells generate energy by fermenting glucose, which generates a great deal of metabolic waste such as lactic acid.

Heavy usage of glucose by fermentation is, in fact, how tumors are identified in PET scans. But if this process is so inefficient, Warburg and others wondered, why do so many organisms depend on it instead of using the more efficient process of aerobic respiration?

A team of physicists and biologists from UC San Diego may have finally found the answer to this nearly 100-year-old mystery. In this week's issue of the journal Nature, the researchers examined the metabolic costs of synthesizing the enzymes and other biological apparatus required for fermentation and aerobic respiration within the bacterium E. coli as well as the metabolic savings of generating energy through aerobic respiration. They found that the cost of protein synthesis overrules the metabolic savings for fast growing cells.

"What we discovered could be compared to the difference between generating energy by a coal factory versus a nuclear power plant," said Terry Hwa, a professor of physics and biology at UC San Diego who headed the study. "Coal factories produce energy less efficiently than nuclear power plants on a per-carbon basis, but they are a lot cheaper to build. So the decision of which route to generate energy depends on the availability of coal and the available budget for building power plants."

"For cells, it turns out that there are also two costs to consider," he added. "One is the cost of raw material. Aerobic respiration generates more energy per carbon atom than fermentation. The other is the opportunity cost of synthesizing enzymes. This cost refers to the number of the protein-making machinery, or ribosomes, that need to be recruited to synthesize the relevant enzymes. We showed that the enzymes for respiration are bulky and slow compared to those for fermentation, so a lot of such enzymes need to be synthesized, tying up a lot of ribosomes, in order for respiration to happen at substantial rates. This is an important cost because the number of ribosomes is the growth limiting factor."

"For fast growing cells with plenty of nutrients, if a lot of ribosomes are used to make respiratory enzymes, then few of them are available to make other growth proteins, including the ribosomes themselves. This would slow down growth and is disadvantageous to cells. The higher carbon efficiency of respiration is not an important consideration here since nutrients are plentiful. On the other hand, when nutrients are scarce and cells cannot grow fast, then the demand for ribosomes by other cellular functions is reduced, and the cost of tying up ribosomes is less important. In the meantime, using respiration to generate energy conserves the precious carbon supplies, which is a much more important consideration in poor nutrient conditions."

"Of these two costs the cell needs to consider when generating energy, the cost of carbon is universally recognized, that is, respiration is more carbon-efficient. What we established in this study is that the cost of making the energy-generating apparatus is also substantial, and is in fact the dominant cost for fast growing cells."

The idea of this opportunity cost to cell growth was first suggested several years ago by a team of theoretical biologists from the Netherlands. In the UC San Diego study, Hwa and his collaborators experimentally characterized the cost of synthesizing fermentation versus respiratory enzymes by using proteomic mass spectrometry and discovered that respiratory proteins are twice as expensive as fermentation proteins for the same rate of energy generation. Their study is the first time such a cost has been established for any living system. The researchers also developed a mathematical model that quantitatively predicted the pattern of metabolic waste excretion in response to perturbations they applied to affect the physiological state of growing cells.

While it is not clear whether the same rationale underlies the origin of "wasteful metabolism" in cancer, the researchers said, they believe their results provide another way to think about the process.

"Instead of something going wrong that should be fixed, this may be the universal strategy necessary for rapidly growing cells," explained Hwa. "The results may also have implications in biotechnology: metabolic engineers are always trying to reduce metabolic waste in engineered organisms in order to reduce cost. Our findings suggest that reducing waste may be detrimental to the organisms and different strategies need to be devised to increase metabolic efficiency."

Other co-authors of the study were UC San Diego scientists Markus Basan, Sheng Hui, Hiroyuki Okano, Zhongge Zhang and Yang Shen, and James Williamson of The Scripps Research Institute in La Jolla. The study was funded by grants from the National Institutes of Health (R01-GM109069), Simons Foundation, Walter Haefner Foundation and the ETH Foundation.

December 02, 2015 | By Kim McDonald

Last modified: 12/03/2015

The B-Mode Story You Haven't Heard

news picture It's a tough time to be a B-mode.

B-modes rocketed to fame in March 2014, when a team of scientists working on an experiment called BICEP2 announced the first direct evidence for primordial gravitational waves rippling out from the earliest moments of the universe: a distinctive imprint in the cosmic microwave background (the light left over from the Big Bang) called "B-mode polarization," or B-modes for short. Polarization describes the way that light-waves are oriented, and B-mode waves are twisted into a swirling pattern. The detection of these swirls was a stunning confirmation of the theory of cosmic inflation. Suddenly, B-modes were electromagnetic celebrities.

Read more of the story at pbs.org

Last modified: 10/31/2015

Researcher Mark Paddock participates in Night of Science at the Fleet Center

news picture A UCSD physics group lead by Dr. Mark Paddock developed and supplied intriguing physics demonstrations for the "Night of Science-Back to the Fleet-ure" event hosted by the Reuben H. Fleet Science Center in Balboa Park.

Levitation, water flowing uphill, bending of light, lightning- all physics demonstrations developed by UCSD physics for the event that took place on October 21st 2105. The UCSD physics group supplied these and other demonstrations beyond the Fleet exhibits to spur the imagination and inquisition of the scientifically intrigued crowd that attended the event. Assisting with the demonstrations were UCSD Physics scientists Brad Hanson, Dr. Eric Michelsen and the group of Dr. Brian Maple, who supplied the superconductors. The Fleet Night of Science is a quarterly after-hours event for anyone over 21. Proceeds from the event support the Fleet's nonprofit mission of "inspiring lifelong learning by furthering the public understanding and enjoyment of science and technology." Mark plans to continue and hopes to extend this relationship in future events. See more at: http://www.rhfleet.org/events/night-science#sthash.SpZLUbqw.dpuf

Details about the event and an interview with Dr. Paddock were broadcast on local television.

You can watch Channel 6's video (which begins with a short advertisement) at http://www.sandiego6.com/san-diego-living/Back-to-the-Future-Science-335195181.html

Dr. Paddock can be reached at mpaddock@ucsd.edu; his website is located at http://physics.ucsd.edu/~mlpfeher/

Last modified: 10/28/2015

Professor Olga Dudko co-recipient of $8.6 million NIH award

news picture Professor Olga Dudko is a co-recipient of an $8.6 million award from the NIH to establish a Center for 4D Nucleome Research at UCSD.

The mission of the new Center is to understand the principles of the structural and functional organization of the mammalian genome in both space and time (hence 4D) by combining advanced techniques of molecular biology and predictive tools of theoretical physics. The Center will be led by three UCSD faculty: Prof. Olga Dudko (UCSD Physics), Prof. Bing Ren (UCSD School of Medicine) and Prof. Kees Murre (UCSD Molecular Biology).

$8.6 million for interdisciplinary study of the 4D Nucleome

UC San Diego faculty from physics, biology and health sciences will lead a new center to unravel the geometry of the genome, precisely track its motion and generate predictive models of how the structure and dynamics govern mammalian genetics.

Bing Ren in health sciences, Cornelis Murre in biological sciences, and Olga Dudko in physical sciences have been awarded $8.6 million for five years to establish the new center, one of six Nuclear Organization and Function Investigation Centers within the NIH 4D Nucleome project.

Human DNA if stretched out would measure two meters long. Inside a cell nucleus just six micrometers wide it coils around proteins to form chromatin, which itself forms loops and bundles that aren't random. Instead the architecture can bring together distant regulatory elements on the string of genetic code to activate or silence specific genes. The pattern of which genes are active varies with the type and state of cells; disruptions of the pattern can lead to disease.

Mapping the three dimensional structure of the genetic material within the nucleus and tracking changes to the arrangement over time-the fourth dimension-are the goals of the 4D Nucleome project.

Bing Ren, professor of cellular and molecular medicine and member of Ludwig Cancer Research, maps contacts between distant elements to build a 3D picture of genomic structure using a technique called Hi-C. By cross-linking nearby chromatin, chopping it into a kind of genetic confetti, sequencing the bits and mapping them back to the sequence of the whole genome, Hi-C reveals which elements were adjacent within the nucleus.

Cornelis Murre, professor of biological sciences, studies the exquisite timing of the system that allows hundreds of genes to be regulated in synchrony. Murre has invented a way to tag specific individual elements of DNA and precisely track their motion in living cells, opening up the possibility to study how DNA elements that regulate genes are finding each other in space. The issue of timing has been little explored, Murre said.

Olga Dudko, associate professor of physics, uses the language of physics to make sense of the avalanche of data from these new techniques that map and track the genome. Dudko develops unifying theories that make concrete predictions. Her goal is to establish the principles that govern structure and dynamics of the mammalian genome. The new center will provide graduate students in theoretical physics with the unique opportunity to directly work with cutting-edge biological data.

Their grant is one of three to UC San Diego from this NIH Common Fund program. Together the campus has garnered more than a quarter of the $120 million allocated to the 4D Nucleome project nationwide.

Last modified: 10/05/2015

Multiple spots in a simulated galaxy glow brightly at submillimeter wavelengths of light

news picture In the new issue of journal Nature, a team of scientists including Dusan Keres (Physics and CASS, UCSD) presents a new supercomputer simulation that can help explain the origin of some of the most extreme objects in the universe, bright submillimeter galaxies.

These objects can form stars with rates up to 1000 times faster than our own Galaxy. Read more in the UCSD press release, an article in LA Times or the paper and related News & Views in Nature.

Continue Reading...

Last modified: 09/25/2015

Astronomers Analyze the Atmosphere of a 'Young Jupiter' Exoplanet

news picture Astronomers have found thousands of planets outside our solar system. Almost all of these exoplanets were detected by measuring periodic changes in the light from their stars.

A newer approach subtracts starlight from the astronomers' view revealing a direct image of the planet itself. The light from the planet, really the glow of its atmosphere, can indicate temperature and composition, clues to how the planet formed.

"We're actually taking pictures of planets, rather than inferring that they're there," said Quinn Konopacky, an assistant professor of physics and member of the Center for Astrophysics and Space Sciences at the University of California, San Diego.

Using the Gemini Planet Imager, mounted on the Gemini South telescope in Chile's astronomical reserve, the team spotted the planet orbiting at about the same distance from its star as Saturn does from the Sun. They report the discovery and describe the planet's atmosphere in a paper published online by Science this week.

The newly discovered planet orbits 51 Eridani, a nearby star a lot like our own, though brighter and much younger, just 20 million years old. And the planet, called 51 Eri b, is like a young Jupiter, a gas giant about twice Jupiter's mass but hotter and even younger than its star.

So in a way, 51 Eridani is an earlier version of a part of our solar system. A closer look could help us understand how planetary systems like ours form.

These observations mean that 51 Eri b could have formed in a process known as "cold start" in which dust gathers first and accretes to a solid core until it reaches a sufficient mass to sweep in gases. A competing scenario, known as "hot start" has both dust and gas coalescing together, which would produce planets that are brighter at young ages.

Further observations, including precise measurement of the planet's orbit, will reveal more about 51 Eri b and its history. The Gemini Planet Imager was designed specifically for discovering and analyzing faint, young planets orbiting bright stars. A team of more than a hundred scientists led by Bruce Macintosh at Stanford University and James Graham at UC Berkeley, continues to search for additional planets around 600 nearby stars.

The National Science Foundation and NASA provide major funding for the Gemini Planet Imager Exoplanet Survey.

Last modified: 08/20/2015

UCSD Physics Professor Wuerthwein and four other investigators bring $5 million, NSF award to UC to establish high speed regional data sharing system

news picture For the last three years, the National Science Foundation (NSF) has made a series of competitive grants to over 100 U.S. universities to aggressively upgrade their campus network capacity for greatly enhanced science data access. NSF is now building on that distributed investment by funding a $5 million, five-year award to UC San Diego and UC Berkeley to establish a Pacific Research Platform (PRP), a science-driven high-capacity data-centric "freeway system" on a large regional scale. Within a few years, the PRP will give participating universities and other research institutions the ability to move data 1,000 times faster compared to speeds on today's inter-campus shared Internet.

Continue reading article....

Last modified: 08/05/2015

Big Bucks for UCSD Big Bang Study: $5M from NSF

news picture A project to study the origins of the universe that is led, in part, by scientists at UC San Diego has won a $5 million grant from the National Science Foundation, the school announced Thursday. The funding to support the Simons Array, which will consist of three powerful telescopes in Chile's Atacama desert, will pay for three years of observation and data analysis of the Big Bang, along with graduate student stipends, undergraduate research scholarships, travel and other operational expenses, according to UCSD.

"People are the heart of any good experiment," said Brian Keating, UCSD professor of physics. "We would not be able to design, fabricate, test and deploy the hardware of the Simons Array - not to mention travel to Chile to observe the distant universe - without the NSF funding."

Keating is leading the project with Adrian Lee, a UC Berkeley professor of physics.

The array is named for James and Marilyn Simons of the Simons Foundation, which provided the initial funding to build and install two telescopes that will join a telescope already in Chile. The three together make up the Simons Array.

According to UCSD, the telescopes will create high-fidelity maps of polarization in the cosmic microwave background, which scientists will analyze for evidence of inflation after the Big Bang.

The CMB is remnant radiation that has cooled and stretched with the expansion of the universe to microwave lengths. The radiation acts as an enormous backlight, illuminating the large-scale structure of the universe and carrying an imprint of cosmic history, UCSD said.

The array is designed to extract faint cosmological systems that are often hidden by dust in the galaxy, which can interfere with other types of telescopes. The new scopes are able to separate the CMB and dust signals by their spectral signatures, according to UCSD.

"The Simons Array represents the boldest, most ambitious and most sensitive instrument ever designed to fully mine the cosmic microwave background of its secrets," Keating said. "With the Simons Array, we have a chance to glimpse the universe in its infancy."

UCSD said the Simons Array will also be the first to measure the masses of neutrinos, the only form of dark matter known to exist. The ghostly particles elude capture, making them difficult to study.

The first of the two new telescopes is scheduled to be deployed later this year and go into use next year, according to school officials.

According to UCSD, the project could still use more funding to support operations and student researchers.

Full Article: http://timesofsandiego.com/tech/2015/06/25/big-bucks-for-ucsd-big-bang-study-5m-from-nsf/

Last modified: 06/30/2015

Incoming Ph.D student Sean Bearden awarded NSF Graduate Student Fellowship

news picture Sean Bearden, incoming UCSD Physics graduate student, has been awarded a NSF Graduate Research Fellowship.

The NSF Graduate Research Fellowship Program recognizes and supports outstanding graduate students in NSF-supported science, technology, engineering, and mathematics disciplines who are pursuing research-based Master's and doctoral degrees at accredited United States institutions.

Find out more about the fellowship at https://www.nsfgrfp.org

Last modified: 06/08/2015

Professor Brian Keating and CASS Associate Research Scientist Kam Arnold to share $5,000,000 NSF Award for the Simons Array Experiment

news picture The POLARBEAR experiment measures polarized fluctuations in the Cosmic Microwave Background (CMB) to search for the signature of gravitational waves from inflation, potentially opening a window on the universe a fraction of a second after the Big Bang. This is a major quest of current physics and astronomy and has broad implications for our understanding of the origin and history of the universe. AST has previously funded the construction, commissioning, and initial operations of the first POLARBEAR 3.5m-diameter telescope at the Atacama desert site near ALMA in Chile. The current award will support commissioning and operations of a second telesope under partnership with the Simons foundation and other collaborating institutions in the US, Japan, Canada, and the UK. The award will support advanced traning for students in instrumentation and facility development. Other broader impacts include educational programs for K-12 students and the general public.

Science goals in addition to B-mode gravitational waves include a search for massive neutrinos, a map of large scale structure in the universe via gravitational lensing, and constraints on the primordial helium abundance and the effective number of relativistic species.

Last modified: 06/05/2015

Against the Stream: Inanimate beads behave in lifelike ways

news picture Scientists have created microbe-sized beads that can utilize energy in the environment to self-propel upstream by purely physical means. Life is hard to define, but metabolism, mobility and replication are three commonly agreed elements. The beads are not alive, but they meet two of these three requirements.

"Living systems change their behavior according to their environment," said Jeremie Palacci, a professor of physics who joined the University of California, San Diego this year. "So the question was, can we design a particle that can sense its environment with no neural system or biological parts. This is a basic feature of living systems, and the idea was to implement that in a synthetic one." Palacci and colleagues wrapped pale polymer around tiny cubes of hematite, a dark mineral of iron and oxygen that protrudes from the spherical beads as a reddish dot. Left alone in a fluid the beads drift with currents, like sticks in a river.

Under blue light the hematite conducts electricity and when bathed in hydrogen peroxide will catalyze a chemical reaction to split oxygen from hydrogen. This sets up chemical gradients, and osmotic flows. The polymer beads surf forward on those flows in the direction of their hematite protrusions. In a still bath the beads follow wavering trajectories as the thermal motion of water molecules buffets them from all sides. This pattern of motion, called a persistent random walk, is analogous to the run-and-tumble motion of bacteria, spermatozoa and algae.

If a pipette streams a flow of the hydrogen peroxide fuel into the bath, the beads surf upstream until their forward momentum is equally countered by the flow from the pipette. The particles encircled the tip of the pipette at a distance where their propulsion was cancelled out by the velocity of the flow, Palacci and colleagues report in the journal Science Advances on May 1. A simple physical model called an overdamped Brownian pendulum describes the pattern and predicts the stagnation point where the beads accumulate.

"What is really cool is that the mechanism we used to get the particles to go upstream actually exists in nature and is used by some parasites to go against flushing flows to colonize bladders," Palacci said. It's an important step toward the realization of biomimetic microsystems with the ability to sense and respond to environmental changes.

Migration along a gradient, called a taxis, is found all over nature. The daily vertical migration of marine plankton toward sunlight, is one example, and it's the way many microbes find food. "If you can design particles that can feel their environment and you went one step further into 'smart' particles that could direct themselves towards specific organs, you could think of particles that swim against the blood stream to fix clogged arteries," Palacci says, adding that such an application is "clearly further down the road."

Co-authors include Stefano Sacanna, Jeremie Barral, Alexander Grosberg, David Pine and Paul Chaikin of New York University, Anais Abramian of Ecole Normale Superieure de Lyon, and Kasey Hanson of Georgia Institute of Technology. The National Science Foundation's Materials Research Science and Engineering Centers program, U.S. Army Research Office, NASA and Moore Foundation funded this research.

Susan Brown

Last modified: 05/11/2015

Former UC San Diego Physics Majors Receive Prestigious NSF Fellowships

news picture Ms. Priscilla Kelly and Ms. Lisa Krayer were awarded NSF Graduate Fellowships to continue their studies in Physics.

While at UC San Diego Ms. Kelly worked in the Keating and Basov Labs. Ms. Krayer also worked with Dr. Keating.

The NSF Graduate Research Fellowship Program recognizes and supports outstanding graduate students in NSF-supported science, technology, engineering, and mathematics disciplines who are pursuing research-based Master's and doctoral degrees at accredited United States institutions.

Last modified: 04/16/2015

Chelsey Dorow receives prestigious NSF Graduate Research Fellowship

news picture Chelsey Dorow, UCSD Physics graduate student, has been awarded a NSF Graduate Research Fellowship.

Chelsey is working with Professor Leonid Butov to study the physics of indirect excitons. Ms. Dorow plans to use the NSF Fellowship to design and fabricate new excitonic devices to study the applications of excitonic circuits and the fundamental physics of cold bosons.

The NSF Graduate Research Fellowship Program recognizes and supports outstanding graduate students in NSF-supported science, technology, engineering, and mathematics disciplines who are pursuing research-based Master's and doctoral degrees at accredited United States institutions.

Find out more about the fellowship at https://www.nsfgrfp.org

Last modified: 04/09/2015

Professors Brian Keating and Mike Norman receive 2014 UC San Diego Diversity Award

news picture Congratulations to Brian Keating and Mike Norman for being nominated by Suresh Subramani - Executive Vice Chancellor of Academic Affairs to receive a 2014 UC San Diego Diversity Award!

The annual Equal Opportunity/Affirmative Action and Diversity Awards Program honors staff, faculty, students, departments, and organizational units or groups that make outstanding contributions in the areas of equal opportunity, affirmative action, diversity, and the UCSD Principles of Community during the year.

Last modified: 04/09/2015

Search for extraterrestrial intelligence extends to new realms

news picture Astronomers have expanded the search for extraterrestrial intelligence into a new realm with detectors tuned to infrared light. Their new instrument has just begun to scour the sky for messages from other worlds.

"Infrared light would be an excellent means of interstellar communication," said Shelley Wright, an Assistant Professor of Physics at the University of California, San Diego who led the development of the new instrument while at the University of Toronto's Dunlap Institute for Astronomy & Astrophysics.

Pulses from a powerful infrared laser could outshine a star, if only for a billionth of a second. Interstellar gas and dust is almost transparent to near infrared, so these signals can be seen from greater distances. It also takes less energy to send the same amount of information using infrared signals than it would with visible light.

The idea dates back decades, Wright pointed out. Charles Townes, the late UC Berkeley scientist whose contributions to the development of lasers led to a Nobel Prize, suggested the idea in a paper published in 1961.

Scientists have searched the heavens for radio signals for more than 50 years and expanded their search to the optical realm more than a decade ago. But instruments capable of capturing pulses of infrared light have only recently become available.

Three years ago while at the Dunlap Institute, Wright purchased newly available detectors and tested them to see if they worked well enough to deploy to a telescope. She found that they did. Jerome Maire, a Fellow at the Dunlap, "turned the screws," Wright said, playing a key role in the hands-on effort to develop the new instrument, called NIROSETI for near-infrared optical SETI.

NIROSETI will also gather more information than previous optical detectors by recording levels of light over time so that patterns can be analyzed to for potential signs of other civilizations, a record that could be revisited as new ideas about what signals extraterrestrials might send emerge.

Because infrared light penetrates farther through gas and dust than visible light, this new search will extend to stars thousands rather than merely hundreds of light years away. And the success of the Kepler Mission, which has found habitable planets orbiting stars both like and unlike our own, has prompted the new search to look for signals from a wider variety of stars.

NIROSETI has been installed at the University of California's Lick Observatory on Mt. Hamilton east of San Jose and saw first light on March 15.

Lick Observatory has been the site of several previous SETI searches including an instrument to look in the optical realm, which Wright built as an undergraduate student at UC Santa Cruz under the direction of Remington Stone, the director of operations at Lick at that time. Dan Werthimer and Richard Treffers of UC Berkeley designed that first optical instrument. All three are playing critical roles in the new search.

NIROSETI could uncover new information about the physical universe as well. "This is the first time Earthlings have looked at the universe at infrared wavelengths with nanosecond time scales," Werthimer said. "The instrument could discover new astrophysical phenomena, or perhaps answer the question of whether we are alone."

The group also includes SETI pioneer Frank Drake of the SETI Institute and UC Santa Cruz who serves as a senior advisor to both past and future projects and is an active observer at the telescope.

Drake pointed out several additional advantages to a search in this new realm. "The signals are so strong that we only need a small telescope to receive them. Smaller telescopes can offer more observational time, and that is good because we need to search many stars for a chance of success." he said. The receivers are also much more affordable that those used on radio telescopes.

"There is only one downside: the extraterrestrials would need to be transmitting their signals in our direction," Drake said, though he sees a positive side to that limitation. "If we get a signal from someone who's aiming for us, it could mean there's altruism in the universe. I like that idea. If they want to be friendly, that's who we will find."

The NIROSETI team also includes Geoffrey Marcy and Andrew Siemion from UC Berkeley; Patrick Dorval, a Dunlap undergraduate, and Elliot Meyer, a Dunlap graduate student. Shelley Wright is also a member of the Center for Astrophysics and Space Sciences at UC San Diego. Richard Treffers is now at Starman Systems. Funding for the project comes from the generous support of Bill and Susan Bloomfield.

By: Susan Brown

Full Story: http://ucsdnews.ucsd.edu/pressrelease/search_for_extraterrestrial_intelligence_extends_to_new_realms

Last modified: 03/25/2015

Schuller Group Research Findings "Giant Magnetic Effects Induced in Hybrid Materials" Published on DOE Website

news picture Giant Magnetic Effects Induced in Hybrid Materials

Novel effects are increasingly being discovered when dissimilar materials are in contact ("hybrids"), often resulting in altogether new phenomena, materials with useful functionalities, or the ability to sense or control important material properties. The focus of this investigation is a hybrid material consisting of a thin nickel film on a vanadium oxide substrate; this hybrid material exhibits magnetic properties unlike any other magnetic material. In this case, the magnetic coercivity (defined as the resistance to a change in the direction of the magnetic fields for a ferromagnetic material) of the nickel reveals insights concerning the transition of the vanadium oxide from being an electrical conductor to becoming an insulator, called the metal-insulator transition (MIT). In turn, the MIT can be used to control the coercivity of the nickel. The vanadium oxide MIT is coincidental with a structural change at a well-defined "transition" temperature. At the thermal midpoint of the transition, crystallites of both phases coexist in equal portions, resulting in maximal structural entropy. The resulting inhomogeneity of the oxide structure causes stresses in the nickel (or other magnetic) film deposited on top. This provides a strong link between the nickel coercivity and the disorder in the oxide. The coercivity is low when the oxide is structurally uniform (above and below the MIT) and high when it is maximally disordered in the middle of the transition. The magnetic properties of nickel therefore provide a window into the MIT process. In turn, the MIT allows dramatic nonmagnetic control of the coercivity, which changes by several hundred percent within a narrow 10 K temperature range, unlike any other known magnetic material. Potential applications have been envisioned in two important, disparate energy related fields: energy driven magnetic recording and self-healing current fault limiters.

Full Article:http://science.energy.gov/bes/highlights/2015/bes-2015-02-g/

Last modified: 03/01/2015

UCSD Physics major Ivanna Escala wins "Special Merit in Research" Award.

news picture Congratulations to all the students for successfully presenting their research and to UCSD Physics major Ivanna Escala for winning a "Special Merit in Research" Award in the Physical Sciences & Engineering category.

A total of 19 UCSD students attended the 2015 CAMP Statewide Undergraduate Research Symposium, which took place on February 6-8 at UC Irvine. Thirteen undergraduate students presented their research in poster format. Several of them were first-time poster presenters. Six undergraduate students attended as observers. Thank you to all of you for representing CAMP @ UC San Diego so well!

I extend a special thank you to the students' faculty and research mentors, who made this step in their academic career possible. Also, I extend my gratitude to Professors Adam Burgasser (Physics), Carlos Coimbra (MAE), Stuart Sandin (SIO), and Kal Seshadri (MAE) for serving (once again!) as UC San Diego judges at this year's symposium. In addition, I would like to thank Professor Olivia Graeve (MAE) for being our keynote speaker at the Awards Dinner.

I would also like to thank and acknowledge Dr. Nzola De Magalhaes (Moores Cancer Center) and Mr. Jordan Davis (Electrical Engineering - Photonics) for assisting with the preparation of students during the pre-symposium logistics meeting in the areas of how to present and how to network at scientific conferences.

A special thank you is also extended to CAMP Statewide for organizing this event, especially to Marjorie DeMartino, Statewide Co-Director, to Dr. Derek Dunn-Rankin, Statewide Co-Director and Lead Judge, and to Jason Gan and Victoria Stinson, CAMP Program Specialists, for overseeing all aspects of this symposium.

Find out more about CAMP here:

Last modified: 02/15/2015

'Frontiers of Innovation' Program Seeds Seven Multidisciplinary Projects at UC San Diego

news picture

An initiative led by the Office of the Chancellor and Research Affairs will help launch seven major research projects on campus, all focused on advancing the university's strategic research goals.

The "Frontiers of Innovation" program is a campus-wide effort to support the primary initiatives of the university's Strategic Plan.

A major component provides funding to support teams of our scholars from all across campus as they work to launch large-scale multidisciplinary research applications.

Our support for these new projects reflects our strong commitment to the research goals articulated in the campus strategic plan. Thanks to the Academic Senate, faculty reviewers, and the Office of Research Affairs, the forward-looking Frontiers of Innovation program will help ensure our continued leadership in research well into the future.

UC San Diego's research enterprise is focused on four broad but strategic goals: understanding and protecting the planet; enriching human life and society; exploring the basis of human knowledge, learning, and creativity; and understanding cultures and addressing disparities in society.

We want to engage all campus members in their efforts to answer basic questions and address the needs of our global society. We were challenged by the large number of applications for this seed funding; however, the faculty review committee identified seven exciting efforts to begin this process.

This year, the Frontiers of Innovation Center Development funds will go to:

Center for Biological Timing in the 21st Century
Led by Michael Gorman, Susan Golden, Satchin Panda
Research area: Understanding and Protecting the Planet

Sustainable Power and Energy Center
Led by Shirley Meng, Oleg Shpyrko
Research area: Understanding and Protecting the Planet

UCSD Center for Translational Computer-Aided Drug Discovery & Project Management
Led by Rommie Amaro, James McKerrow
Research area: Enriching Human Life and Society

UCSD Center for Compound Resources
Led by William Gerwick, Dionicio Siegel
Research area: Enriching Human Life and Society

Institute for Integrative Science of the Developing Mind and Brain
Led by Jeff Elman, Susan Tapert
Research area: Exploring the Basis of Human Knowledge, Learning, and Creativity

Center for Research on Gender in STEMM
Led by Mary Blair-Loy, Wendy Campana, Pamela Cosman
Research area: Understanding Cultures and Addressing Disparities in Society

The UC San Diego Community Stations
Led by Angela Booker, Fonna Forman, Teddy Cruz
Research area: Understanding Cultures and Addressing Disparities in Society

A second major component of the campus investment in our research future is the Frontiers of Innovation Scholars Program, which focuses on supporting students working in areas key to UC San Diego's future. The FISP program provides fellowships for undergraduate and graduate students as well as postdoctoral scholars working on major multidisciplinary research projects.

These creative and ambitious faculty efforts will help us take a bold step toward meeting the grand challenges facing the world today.

Last modified: 01/30/2015

Statistical Mechanics of Viral Invasion Strategy

news picture Professor Olga Dudko and graduate student Yajoun Zhang developed a theory that explains quantitatively how viruses can infect cells on remarkably short time scales despite high energy barriers. Viruses that have lipid-membrane envelopes - such as HIV and influenza - infect cells by fusing with the cell membrane to release viral genes.

Membrane fusion is known to be a highly energetically unfavorable process - yet viral infection, which occurs by fusion, proceeds on a time scale of minutes. In their article, published in a recent issue of Physical Review Letters, Zhang and Dudko presented a statistical-mechanical theory that captures the principles behind the invasion strategy shared by all enveloped viruses.

The key to this remarkably efficient strategy is a set of viral "fusion proteins" that serve the required role of a catalyst in the fusion process.

Once exposed to a trigger, such as low pH or cell receptors, the proteins, anchored in the viral membrane, insert into the target membrane and then refold, harnessing the energy liberated by the refolding to pull the membranes together.

In addition to viral infection, the same principles operate in rapid neuronal communication enabled by calcium-triggered fusion of synaptic vesicles with a cell, as well as during fertilization, development, and immune responses, all of which involve fusion between cells. The authors illustrated the predictive value of their theory through recent experimental data on influenza virus infection.

Full Journal article link:

Last modified: 01/21/2015

Study Sheds Light on What Causes Cells to Divide

news picture When a rapidly-growing cell divides into two smaller cells, what triggers the split? Is it the size the growing cell eventually reaches? Or is the real trigger the time period over which the cell keeps growing ever larger?

A novel study published online today in the journal Current Biology has finally provided an answer to this long unsolved conundrum. And it's not what many biologists expected.

"How cells control their size and maintain stable size distributions is one of the most fundamental, unsolved problems in biology," said Suckjoon Jun, an assistant professor of physics and molecular biology at UC San Diego, who headed the research study with Massimo Vergassola, a professor of physics. "Even for the bacterium E. coli, arguably the most extensively studied organism to date, no one has been able to answer this question."

Finding a solution was more than a basic-science pursuit for the scientists, who pointed out that learning more about the triggers of cell division would enable researchers to better understand such processes as the runaway cell division that leads to cancer. To conduct the study, Jun and his colleagues developed a tiny device to isolate and physically manipulate individual genetic materials.

"It turned out that we can use this device to also follow the life history of thousands of individual bacterial cells for hundreds of generations," he said. "We looked at the growth patterns of the cells very, very carefully, and realized that there is something really special about the way the cells control their size."

"In our study, we monitored the growth and division of hundreds of thousands of two kinds of bacterial cells, E. coli and B. subtilis, under a wide range of tightly controlled steady-state growth conditions," said Jun. "This produced statistical samples about three orders of magnitude, or a thousand times better, than those previously available. We could thus pursue an unprecedented level of quantitative analysis."

The scientists found through their development of mathematical models that matched their experimental data that the growth of cells followed the growth law, essentially exponential growth based on a constant rate. But they also found to their surprise that cell size or the time between cell divisions had little to do with when the cells divided. Instead, to keep the distribution of different sized cells within a population constant, the cells followed what the researchers termed "an extraordinarily simple quantitative principle of cell-size control."

"Specifically, we showed that cells sense neither space nor time, but add constant size irrespective of their birth size," said Jun. "This 'adder' principle automatically ensures stability of size distributions."

"E. coli and B. subtilis are one billion years divergent in evolution, and they are the textbook examples of the diversity of molecular details for biological controls in different bacterial species. Thus, their sharing the same quantitative principle for size maintenance is a textbook level discovery."

The two primary authors of the study were Sattar Taher-Araghi of UC San Diego and Serena Bradde of the City University of New York. In addition to Jun and Vergassola, other co-authors are John T. Sauls of UC San Diego, Norbert S. Hill of UC Berkeley, Petra A. Levin of Washington University and Johan Paulsson of the Harvard Medical School.

Jun's research effort was supported by a $240,000 grant from the Pew Charitable Trusts and a $1.6 million award from the Paul G. Allen Family Foundation, established by one of the co-founders of Microsoft. He also received a $1.15 million grant from the National Science Foundation to apply, together with his graduate students, the work from their research on cell division to annual "boot camps" that will educate San Diego-area high school and college students about an emerging field at the intersection of physics and biology called "quantitative biology"--in which the mathematical models of physics are used to simulate biological phenomenon. This mathematically based, quantitative biology approach was used to solve the problem of what prompts cells to divide.

"Quantitative biology is more than adding numbers to what biologists already know," explained Jun. "The power of the approach is to bring quantitative rigor from physical sciences to identify and solve important and interesting problems in biology."

By: Kim McDonald

Last modified: 01/07/2015

San Diego linked to major moments, from Ebola fight to Big Bang claim

news picture Oh, what sweet agony.

Brian Keating knew early this year that scientists appeared to have found an echo of the Big Bang, or birth of the universe. But the UC San Diego physicist couldn't discuss it until the news was formally unveiled at Harvard University on March 17.

"There was tremendous pressure not to reveal the secret," said Keating, who helped to design and build BICEP 2, the telescope tied to the discovery. "If I had had to wait another week, I would have gone crazy!"

Harvard's John Kovac announced that a team of scientists had captured evidence that the universe began to rapidly expand shortly after the Big Bang, a phenomenon known as cosmic inflation. The claim was based on data collected by BICEP 2.

The news shook physics. But it didn't solve anything. At least, not yet.

Other researchers have challenged the findings, and the Harvard researchers have tempered their announcement, something Keating had been urging them to do from the beginning.

"This is a great discovery - if it can be confirmed," Keating said.


Last modified: 01/05/2015

Led by Professors Brian Keating and Hans Paar POLARBEAR Detects Curls in the Universe's Oldest Light

news picture Cosmologists have made the most sensitive and precise measurements yet of the polarization of the cosmic microwave background.

The report, published October 20 in the Astrophysical Journal, marks an early success for POLARBEAR, a collaboration of more than 70 scientists using a telescope high in Chile's Atacama desert designed to capture the universe's oldest light.

"It's a really important milestone," said Kam Arnold, the corresponding author of the report who has been working on the instrument for a decade. "We're in a new regime of more powerful, precision cosmology." Arnold is a research scientist at UC San Diego's Center for Astrophysics and Space Sciences and part of the cosmology group led by physics professor Brian Keating.

POLARBEAR measures remnant radiation from the Big Bang, which has cooled and stretched with the expansion of the universe to microwave lengths. This cosmic microwave background, the CMB, acts as an enormous backlight, illuminating the large-scale structure of the universe and carrying an imprint of cosmic history.

Arnold and many others have developed sensitive instruments called bolometers to measure this light. Arrayed in the telescope, the bolometers record the direction of the light's electrical field from multiple points in the sky.

"It's a map of all these little directions that the light's electric field is pointing," Arnold explained.

POLARBEAR has now mapped these angles with resolution on a scale of about 3 arcminutes, just one-tenth the diameter of the full moon..

The team found telling twists called B-modes in the patterns of polarization, signs that this cosmic backlight has been warped by intervening structures in the universe, including such mysteries as dark matter, composed of substance that remains unknown, and the famously aloof particles called neutrinos, which elude capture making them difficult to study.

This initial report, the result of the first season of observation, maps B-modes in three small patches of sky.

Dust in our own galaxy also emits polarized radiation like the CMB and has influenced other measurements. But these patches are relatively clean, Arnold says. And variations in the CMB polarization due to dust occur on so broad a scale that they do not significantly influence the finer resolution B-modes in this report.

"We are confident that these B-modes are cosmological rather than galactic in origin," Arnold said.

Observations continue, and the data stream will ultimately be fed by additional telescopes comprising the Simons Array. Together they will map wider swaths of the sky, making fundamental discoveries possible.

"POLARBEAR is a real tour de force. With a relatively small, but strong, UC-led team we have surpassed the next-nearest competitors by an order of magnitude in sensitivity. We have paved the way towards solving the deepest mysteries in the quest to understand matter and energy at the beginning of time," said Brian Keating.

POLARBEAR is a collaboration of scientists from many institutions including experiment founder, Adrian Lee, professor of physics at UC Berkeley.

The National Science Foundation provided major funding for the project. Additional funding included support by the James B. Ax Family Foundation and the Simons Foundation.

Last modified: 10/23/2014

Quantum Design Supports UC San Diego Physics Students with $279,000 Gift

news picture Physics majors at the University of California, San Diego will have the opportunity to gain experience and training on the same high-tech tools that industry researchers use, thanks to contributions from Quantum Design. The San Diego-based technology company which has strong alumni ties to the campus is providing in-kind and cash gifts totaling $279,000 to update and modernize lab courses and instructional materials in the department of physics.

"UC San Diego department of physics alumni have played important roles in leadership, research and development at Quantum Design," said Chief Technical Officer Stefano Spagna, who earned his Ph.D. in materials science from the campus in 1995. "We know that the ability for UC San Diego students to have direct access to state-of-the art research equipment and technology, coupled with instruction in the foundations of physics, creates an ideal training ground for the next generation of physicists to work in numerous fields."

Co-founded by UC San Diego alumnus Ronald Sager, Quantum Design specializes in the manufacturing of complex measurement instruments used in fundamental research of materials. Its tools are used by universities and research labs worldwide to study the characteristics of materialsoften at very extreme temperaturesand have become the reference standard for magnetics and physical property measurements.

Both Spagna and Neil Dilley, applications physicist at Quantum Design, did their graduate studies with UC San Diego professor Brian Maple. They credit the experience with teaching them to be persistent in problem solving, to think critically and to drive their own research projectsqualities that have helped them to be successful in their professional careers.

"Part of this gift is about giving back to the university, and to the prestigious physics department that taught us so much," said Dilley, who earned his Ph.D. in physics in 1999. "We want to do our part to help educate and train today's students."

The department of physics and Quantum Design are collaborating to develop new curriculum for undergraduates that will provide practical experience using the latest industry research tools. In addition to learning the tools, the training is intended to teach students how to use their physics background to think critically about scientific experiments, rather than taking a passive, "push-button" approach to conducting research.

"Thanks to the generosity of Quantum Design, a long-term partner of the UC San Diego physics department, we have been able to bring 21st century instruments for materials discovery into a teaching lab designed for our undergraduate students," said Dimitri Basov, chair of the department of physics. "We are grateful to have the support of alumni like Stefano and Neil, who are committed to creating opportunities for the next generation."

Over the years, close to 100 UC San Diego students have interned with Quantum Design. In 2012, the company established the Ronald E. Sager Young Scientist Scholarship to support a female student in physics. Ivy Lum, the inaugural recipient of the award, recently completed graduate studies in the materials science and engineering program with a Master of Science degree, and is now working at Quantum Design.

Last modified: 10/23/2014

Dimitri Basov selected "Experimental Investigators in Quantum Materials" by The Gordon and Betty Moore Foundation

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The Gordon and Betty Moore Foundation, after a national competition, has selected nineteen Moore Experimental Investigators in Quantum Materials. Through grants to 11 universities around the United States, this five-year, $34.2 million investigator program will allow these outstanding physicists to pursue ambitious, high-risk research, including the development of new experimental techniques. The program could transform our understanding of quantum materials and make it possible to ask fundamentally new questions about how complex quantum matter organizes and behaves.

Quantum materials are substances in which collective behavior of electrons leads to many emergent properties, such as high-temperature superconductivity and exotic forms of magnetism. New discoveries in this field could eventually lead to revolutionary applications in electronics, computing, energy technology and medical devices.

The Moore Experimental Investigator in Quantum Materials Awards are part of a $90 million Emergent Phenomena in Quantum Systems (EPiQS) Initiative - one of the largest privately-funded initiatives in this field - that provides support for highly talented scientists in three areas: experiment, materials synthesis and theory. The EPiQS Initiative aims to facilitate scientific breakthroughs by giving some of the fieldss most creative scientists the freedom to take risk and the flexibility for agile change of research direction, and providing them with an environment that encourages collaboration with other leading researchers. Earlier this year, the Moore Foundation announced the winners of its competitions for Materials Synthesis Investigators and Theory Centers.

Full Article: here

Last modified: 09/30/2014

UC San Diego Physics 2014 Edition Newsletter Available Now

news picture Download the latest edition of our 2014 Newsletter here:

2014 Newsletter

Last modified: 09/08/2014

Radio telescopes settle controversy over distance to star cluster

news picture A satellite called Hipparcos, launched in 1989, measured the distances to clusters of stars and found that one cluster, familiar to stargazers as the Pleiades, was 10 percent closer than everyone had thought. That suggested its stars must be fainter than stellar models predict. A debate ensued about whether the model or the measure was wrong.

Now Carl Melis, a research scientist with the Center for Astrophysics and Space Sciences, and colleagues from other institutions have seemingly put the matter to rest. In the August 29th issue of Science, they report a distance derived from very-long-baseline radio interferometry that agrees well with previous ground-based determinations — and not with Hipparcos. Read more at Sky and Telescope.

Last modified: 09/08/2014

Professor Ivan Schuller 2014 IEEE Distinguished Lecturer

news picture The IEEE Distinguished Lecturers are engineering professionals who help lead their fields in new technical developments that shape the global community. The Principal Criteria for selection as a DL are:

Excellence in some field of magnetics. This is not limited to excellence in research, but should also recognise the important contributions of individuals in developing the applied/technical aspects of magnetics.

Excellent communication skills.

The Distinguished Lecturer (DL) Program of the IEEE Magnetics Society has been in existence since 1980. On a yearly basis one or more DLs are chosen and funded by the Magnetics Society to deliver lectures on magnetism and related topics to Universities, Magnetics Society Chapters, Companies, and National Laboratories around the globe that have an interest in topics related to magnetism. Throughout its existence the program has delivered an excellent series of enthusiastic and authoritative lecturers

Last modified: 09/08/2014

Grad student Yaojun Zhang aids Quantitative Biology approach which reveals importance of physical constraints on critical DNA interaction

news picture Our immune system copes with a multitude of threats using a mix-and-match system to create millions of different antibodies.

The white blood cells that produce these antibodies assemble their specific versions by selecting three gene segments from among multiple variants.

Joseph Lucas, a graduate student working with Cornelis Murre, a professor of biology at UC San Diego, tagged individual gene segments in live cells to track their movement in three dimensions.

To better understand what they observed, the biologists turned to Yaojun Zhang, a graduate student in physics and her advisor, Olga Dudko, a professor of physics at UC San Diego, who analyzed the movements. They recognized the patterns as 'fractional Langevin motion.'

Rather than diffusing freely, like milk in black coffee, the movement of the elements is hindered by the mesh of proteins and nucleic acids inside the cell and the element's attachment to stretchy chromatin fibers.

As a result of this viscoelastic quality of their environment, the gene segments likely bounce back and forth in a spring-like fashion until they meet and establish an interaction.

Numerical simulations of the motions using fractional Langevin equations revealed how long it would take for individual genomic elements to first meet. Just seconds to minutes, hours at the outset, the team reported in a recent issue of Cell.

That's quick, and the main factor seems to be that elements, though strung out separately along the chromatin, remain confined to a common genomic neighborhood.

We know from previous work that chromosomes fold into territories that rarely intermingle. These bundles of loops likely constrain movements and determine the timing of contacts between different genetic elements.

The importance of interactions between distant genetic elements goes beyond the production of antibodies. Regulatory elements control far flung coding elements to specify the suite of proteins made by particular types of cells. And the kind of genetic editing that creates highly specific antibodies sometimes goes awry causing breaks in DNA that can lead to cancer.

The National Institutes of Health and National Science Foundation supported this work.


Last modified: 08/14/2014

Ivan Schuller appointed as Sackler Professor at Tel Aviv University

news picture Over 30 major projects at Tel Aviv University bear the stamp of Dr. Raymond Sackler and his family, including the Sackler Faculty of Medicine, the Raymond and Beverly Sackler Faculty of Exact Sciences, and the Mortimer and Raymond Sackler Institute of Advanced Studies, as well as research institutes, chairs, lectureships, prizes, and works of art.

With keen insight into the University's potential, Dr. Sackler and his wife Beverly have promoted growth in the sciences, humanities, and arts, and have contributed immensely to shaping the intellectual life of the campus.
The Raymond & Beverly Sackler Program for Senior Professors by Special Appointment is a new Sackler initiative dedicated to building a preeminent faculty at Tel Aviv University, and serves as a model of excellence for the worldwide scientific community.


Professor Lucian Arye Bebchuk - Law and Economics
Professor Richard Bersohn - Chemical Physics
Professor Imrich Chlamtac - Telecommunications
Professor S.A.P.L Cloetingh - Tectonics and Geophysics
Professor Francois Englert - Physics
Professor Mikhael Gromov - Mathematics
Professor Ian Charles Jarvie - Philosophy and Mass Media
Professor Joseph Katz - Hydromechanics
Professor David M. Kreps - Microeconomic theory, Game theory, and Economic Modeling
Professor Itzhak Kronzon - Cardiology
Professor Jacob Lassner - Jewish Studies
Professor Alex Muller - Solid-State Physics
Professor William E. Paul - Immunology, Allergy and Cancer Research
Professor Boris Rubinsky - Biomedical Engineering

Last modified: 08/14/2014

Vanishing Viscosity: A superfluid gas formed in layers of 2D crystals could induce superconductivity at high temperatures

news picture An elusive state of matter called superconductivity could be realized in stacks of sheetlike crystals just a few atoms thick, a trio of physicists has determined.

Superconductivity, the flow of electrical current without resistance, is usually found in materials chilled to the most frigid temperatures, which is impractical for most applications. It's been observed at higher temperatures-higher being about 100 kelvin or minus 280 degrees below zero Fahrenheit-in copper oxide materials called cuprate superconductors. But those materials are brittle and unsuitable for fabricating devices like circuits.

In a paper published in Nature Communications the week of July 28, Michael Fogler and Leonid Butov, professors of physics at the University of California, San Diego, and Konstantin Novoselov, Nobel laureate in physics and professor at the University of Manchester, propose a design for an artificially structured material that should support superconductivity at temperatures rivaling those seen for cuprates.

They considered a material made by interleaving two different types of crystal, one a semiconductor compound and the other a type of insulator. Two one-atom thick layers of the semiconductor compound molybdenum disulfide would be separated by a few-atom thick spacer made of boron nitride, and surrounded by additional boron nitride cladding.

This sets up a situation in which electrons and "holes" left by a missing electrons would accumulate in separate layers of the semiconductor compound in response to an electrical field. And yet these separated electrons and holes would be bound, at a distance, in states called indirect excitons.

These indirect excitons would form a gas with vanishing viscosity. That is, below a certain temperature, the gas would become superfluid. The physicists determined that superfluidity of indirect excitons would set up countercurrents that would not dissipate, a phenomenon called counterflow superconductivity.

Superfluidity and superconductivity are macroscopic manifestations of quantum phenomena, which are usually seen at the smallest physical scales.

The proposed design is an initial blueprint, the authors write. Their analysis reveals a general principle for creating "coherent states" like superfluidity and superconductivity that would emerge in similar materials created with layers of other semiconductor compounds such as tungsten disulfide or tungsten diselenide as well.

Such van der Waals structures are the subject of many investigations; this new analysis demonstrates that they also provide a new platform for exploring fundamental quantum phenomena.

Practical uses are possible as well; these materials could be used to develop electronic and optoelectronic circuits.

The U.S. Office of Naval Research, University of California Office of the President, U.S. National Science Foundation, European Research Council and the European Commission's Future and Emerging Technologies European Graphene Flagship supported this work.

Media Contact: Susan Brown sdbrown@ucsd.edu 858.246.0161

Last modified: 07/29/2014

Relaxation Helps Pack DNA into a Virus

news picture Taking a moment to pause and relax can help if you find yourself in a tight spot. This strategy can work for molecules as well as people, it turns out.

Researchers at the University of California, San Diego have found that DNA packs more easily into the tight confines of a virus when given a chance to relax, they report in a pair of papers to be published in in the early edition of the Proceedings of the National Academy of Sciences the week of May 26 and the May 30 issue of Physical Review Letters.

DNA is a long, unwieldy molecule that tends to repel itself because it is negatively charged, yet it can spool tightly. Within the heads of viruses, DNA can be packed to near crystalline densities, crammed in by a molecular motor.

"These are among the most powerful molecular motors we know of," says Douglas Smith, a professor of physics whose group studies them.

Within an infected cell, viruses assemble in a matter of minutes. Smith's group studies the process by isolating components of this system to watch single molecules in action.

They attach the empty head of a single virus, along with the molecular motor, to a microscopic bead that can be moved about using a laser. To another bead, they tether a molecule of viral DNA.

"It's like fishing," Smith says. "We dangle a DNA molecule in front of the viral motor. If we're lucky, the motor grabs the DNA and starts pulling it in."

Packaging proceeds in fits and starts, with slips and pauses along the way. These pauses increase, along with forces the motor counters, as the viral head becomes full.

Scientists who model this process have had to make assumptions about the state of the DNA within. An open question is whether the DNA is in its lowest energy state, that is at equilibrium, or in a disordered configuration.

"In confinement, it could be forming all kinds of knots and tangles," said Zachary Berndsen, a graduate student in biochemistry who works with Smith and is the lead author of the PNAS paper.

To figure this out, the researchers stalled the motor by depriving it of chemical energy, and found that packaging rates picked up when the motor restarted. The longer the stall, the greater the acceleration.

DNA takes more than 10 minutes to fully relax inside the confines of a viral head where there's little wiggle room, they found. That's 60,000 times as long as it takes unconfined DNA to relax.

"How fast this virus packages DNA is determined by physics more than chemistry," Smith said.

DNA's tendency to repel itself due to its negative charge may actually facilitate the relaxation. In related experiments, the researchers added spermidine, a positively charged molecule that causes DNA in solution to spool up.

"You might think the stickiness would enhance packing, but we find that the opposite is true," said Nicholas Keller, the lead author of this second report, published in Physical Review Letters.

Countering the negative charges, particularly to the point of making the DNA attractive to itself, actually hindered the packaging of DNA.

"The DNA can get trapped into conformations that just stop the motor," Keller said.

"We tend to think of DNA for its information content, but living systems must also accommodate the physical properties of such a long molecule," Berndsen said. "Viruses and cells have to deal with the forces involved."

Beyond a clearer understanding of how viruses operate, the approach offers a natural system that is a model for understanding and studying the physics of long polymers like DNA in confined spaces. The insights could also inform biotechnologies that enclose long polymers within minuscule channels and spheres in nanscale devices.

Shelley Grimes and Paul Jardine, microbiologists at the University of Minnesota co-authored both papers. Damian delToro, a graduate student in physics at UC San Diego, co-authored the paper published by Physical Review Letters.

The National Science Foundation and the National Institute of General Medical Sciences funded the work.

Last modified: 06/13/2014

Dianna Cowern wins "Flame Challenge"

news picture Dianna Cowern, who has been organizing various outreach activities for the department of physics, has just struck gold by winning the Flame Challenge at the World Science Festival in NYC this past weekend. The Challenge is hosted by the Alan Alda Center for Communicating Science at Stony Brook University, but her video was selected by 27,000 middle school kids across the world. As part of his annual Flame Challenge, actor-turned-science-advocate Alan Alda invited scientists to come up with accurate, vivid answers to the deceptively simple question, "What is color?" On Sunday, Alda announced the winners here at the World Science Festival during an event that explored what color is (and isn't) made of, how the brain perceives it, and how some individuals can even "see" it in music and smells.

See Dianna's winning entry here:


Last modified: 06/10/2014

Professor Eva-Maria Collins selected as a 2014-2015 Hellman Fellow

news picture The Hellman Fellows Fund supports junior faculty research on the ten campuses of the UC system and at four private institutions. The Hellman Fellowship program has three objectives:

To support and guide an early-career professional who wants to develop expertise on issues of science, engineering and technology policy;

To increase the number of science-policy professionals who are engaged in substantive discussion of science and engineering research questions, with a broad understanding of their social implications; and

To expand the scale of Academy projects and studies focused on challenges facing scientific research and science education.

Last modified: 05/23/2014

Professor Adam Burgasser receives Faculty Mentor Program Outstanding Mentor Award for 2014

news picture Honorees were selected based on a combination of factors, including student testimonials, innovative or unusual mentoring practices, and other considerations, such as mentees served and years of service as a mentor to undergraduates. All mentors provide excellent instruction and guidance to their respective students and receive the very great gratitude of the program staff.

Last modified: 05/23/2014

Radiation from Early Universe Found Key to Answer Major Questions in Physics

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Astrophysicists at UC San Diego have measured the minute gravitational distortions in polarized radiation from the early universe and discovered that these ancient microwaves can provide an important cosmological test of Einstein's theory of general relativity. These measurements have the potential to narrow down the estimates for the mass of ghostly subatomic particles known as neutrinos.

The radiation could even provide physicists with clues to another outstanding problem about our universe: how the invisible "dark matter" and "dark energy," which has been undetectable through modern telescopes, may be distributed throughout the universe.

The scientists are publishing details of their achievement in the June issue of the journal Physical Review Letters, the most prestigious journal in physics, which highlighted their paper as an "editor's suggestion" because of its importance and significance to the discipline.

The UC San Diego scientists measured variations in the polarization of microwaves emanating from the Cosmic Microwave Background-or CMB-of the early universe. Like polarized light (which vibrates in one direction and is produced by the scattering of visible light off the surface of the ocean, for example), the polarized "B-mode" microwaves the scientists discovered were produced when CMB radiation from the early universe scattered off electrons 380,000 years after the Big Bang, when the cosmos cooled enough to allow protons and electrons to combine into atoms.

Astronomers had hoped the unique B-mode polarization signature from the early cosmos would allow them to effective "see" portions of the universe that are invisible to optical telescopes as gravity from denser portions of the universe tug on the polarized light, slightly deflecting its passage through the cosmos during its 13.8 billion year trip to Earth. Through a process called "weak gravitational lensing," the distortions in the B-mode polarization pattern, they hoped, would allow astronomers to map regions of the universe filled with invisible "dark matter" and "dark energy" and well as provide a test for general relativity on cosmological scales.

The recent discovery confirms both hunches. By measuring the CMB polarization data provided by POLARBEAR, a collaboration of astronomers working on a telescope in the high-altitude desert of northern Chile designed specifically to detect "B-mode" polarization, the UC San Diego astrophysicists discovered weak gravitational lensing in their data that, they conclude, permit astronomers to make detailed maps of the structure of the universe, constrain estimates of neutrino mass and provide a firm test for general relativity.

"This is the first time we've made these kinds of measurements using CMB polarization data," said Chang Feng, the lead author of the paper and a physics graduate student at UC San Diego who conducted his study with Brian Keating, an associate professor of physics at the university and a co-leader of the POLARBEAR experiment. "This was the first direct measurement of CMB polarization lensing. And the amazing thing is that the amount of lensing that we found through these calculations is consistent with what Einstein's general relativity theory predicted. So we now have a way to verify general relativity on cosmological scales."

The POLARBEAR experiment examined a small (30 degree square) region of the sky to produce high resolution maps of B-mode polarization, which enabled the team to determine that the amplitude of gravitational fluctuations they measured was consistent with the leading theoretical model of the universe, known as the Lambda Cold Dark Matter cosmological model. Another team Keating's group collaborates with, based at the Harvard-Smithsonian Center for Astrophysics, called BICEP2, used a telescope at the South Pole to examine B-mode polarization across wide swaths of the sky. In March, it announced it had found evidence for a brief and very rapid expansion of the early universe, called inflation.

One of the most important questions in physics that can be addressed from these data is the mass of the weakly interacting neutrino, which was thought to have no mass, but current limits indicate that neutrinos have masses below 1.5 electron volts. Feng said the B-mode polarization data in his study, while consistent with the predictions of general relativity, are not statistically significant enough yet to make any firm claims about neutrino masses. But over the next year, he and Keating hope to analyze enough data from POLARBEAR, and its successor instrument - the Simons Array- to provide more certainty about the masses of neutrinos.

"This study is a first step toward using polarization lensing as a probe to measure the mass of neutrinos, using the whole universe as a laboratory," Feng said.

"Eventually we will be able to put enough neutrinos on a 'scale' to weigh them-precisely measuring their mass," Keating says. "Using the tools Chang has developed, it's only a matter of time before we can weigh the neutrino, the only fundamental elementary particle whose mass is unknown. That would be an astounding achievement for astronomy, cosmology and physics itself."

The study was supported by grants from the National Science Foundation, National Aeronautics and Space Administration, the Simons Foundation, and Irwin and Joan Jacobs.

Source: http://ucsdnews.ucsd.edu/pressrelease/radiation_from_early_universe_found_key_to_answer_major_questions_in_physic

Other Articles About This Discovery:

Last modified: 05/15/2014

Professor Tom Murphy receives Sustainability Award at UC San Diego

news picture In celebration of UC San Diego's Earth Week, April 21-25, 2014, the Advisory Committee on Sustainability recognized UC San Diego Physics Professor Tom Murphy.

Professor Murphy developed an awareness of the acute challenges facing our society by teaching Physics 12, Energy and the Environment, at UCSD beginning in 2004. Since then, he and his wife have transformed their lives into a low-resource-use experiment, reducing home energy usage by a factor of five, harvesting rainwater, raising chickens for eggs, growing food, experimenting with off-grid solar power, and changing dietary and travel habits for a lower impact.

Applying physics skills (honed in his research testing General Relativity) to societal-scale problems, Professor Murphy initiated a popular blog called Do the Math to explore the challenges of the 21st century. Together with various published articles and talks at conferences and other schools, "Tom represents UC San Diego's sustainability ideals to the outside world," as one of his colleagues commented.

Last modified: 04/28/2014

Unveiling the Universe's Earliest Secrets

news picture It's the faintest light, yet it carries information from the beginning of time.

A telescope trained on the Antarctic sky has picked up swirling patterns of light believed to be the imprint of the violent expansion of the universe a trillionth of a second after it burst into being.

Excitement swept the scientific community following the March 17 announcement, tempered by caution. If the signal is real, the discovery is the first evidence of an idea proposed three decades ago and possibly worthy of a Nobel Prize. But before any prizes are awarded, the finding must be confirmed by another instrument.

Brian Keating, an associate professor of physics at UC San Diego and a member of the team that made the discovery, also leads another project that could make those necessary observations, and more.

"POLARBEAR is poised to confirm the findings of the BICEP2 telescope, but will also measure masses of cosmic neutrinos, the 'ghostly messengers' of the Big Bang," says Keating, who leads this multi-institutional collaboration along with Adrian Lee, a professor of physics at UC Berkeley.

Despite its name, POLARBEAR is based closer to the equator than either pole, and there's nothing ursine about it. The name is a play on the signal the telescope was designed to detect: polarization of background radiation. That is, the cosmic microwave background radiation, the afterglow of the Big Bang that pervades the entire visible universe.

That ancient light was trapped in a fog of particles for 380,000 years until the cosmos cooled enough to allow the first atoms to form and light to escape. Like the glare of light glancing off of the surface of a lake, this early light carries an imprint of the texture of space in its patterns of polarization.

Distinctive swirls in that pattern are what caused all the excitement a few weeks ago. This curling light is just what cosmologists expected to see, a trace left by gravitational waves - ripples in the fabric of space - wrought by the faster-than-light ballooning of the universe in its first moment.

It's also a signal to probe for details of how this epoch in the history of the universe, invisible to us before now, unfolded. POLARBEAR is set to be part of that exploration, and to extract even more information from these wispy signals.

The sign of inflation is like a palimpsest, a faint primordial trace obscured by the influence of more recently formed structures - clusters of galaxies and even dust in the Milky Way. These subsequent traces were carefully peeled back to reveal the original imprint of inflation, but they aren't noise.

Instead, the cosmic microwave background radiation acts like an enormous backlight that can reveal the composition of the universe. Measuring that composition will lead to further fundamental discoveries such as the masses of neutrinos, notoriously aloof particles that rarely interact with other matter, making their capture nearly impossible.

Right now, the POLARBEAR project has a single telescope that has been scanning the sky since January 2012. By the end of 2015, it should be joined by two more, collectively the Simons Array, which will boost its light-gathering power, allowing it map and measure the contents of the universe and to delve deeper into the question of what happened at the beginning of time.

Visit the POLARBEAR project website to learn more.

By Susan Brown

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Last modified: 04/17/2014

April 2014 Lunar Eclipse Laser Ranging

news picture UCSD Physics Professor Tom Murphy and his team shot a laser at the reflectors left on the lunar surface by the Apollo astronauts during the recent lunar eclipse on April 15, 2014. In addition to testing Einstein's General Relativity, eclipse operations allow insight into the layer of dust that has formed on the reflectors these past four decades (see http://ucsdnews.ucsd.edu/feature/source_of_moon_curse_revealed_by_eclipse).

Last modified: 04/16/2014

Congressman Recognizes Historic Discovery On Origins Of The Universe, Advocates For Scientific R&D on the House Floor

news picture Congressman Bill Foster (IL-11) speaks on the House floor to recognize an important advancement in scientific research. Recently the BICEP2 team announced its discovery of scientific evidence for cosmic inflation in the early universe. This evidence supports a specific version of the Big Bang model of the universe-a cosmic explosion followed immediately by expansion. Scientists have hypothesized that the universe underwent a period known as inflation immediately following the Big Bang, in which the universe exponentially expanded in size. The discovery by the BICEP2 team provides evidence that appears to support this theory of inflation.

Read More

Last modified: 04/09/2014

Cosmic Inflation Explained In Comic Strip

news picture Jon Kaufman (soon to be Dr. Jon Kaufman) is a member of the BICEP2 team that made the discovery described below. As one of the Ph.D. students in the project, Jon spent many months in the South Pole (there is an actual pole), recharging the liquid Helium on the telescope, for which he received a medal. It was his idea to draw this comic.


Jonathan Kaufman, a graduate student at UC San Diego, helped to design, build, test and deploy BICEP2. He traveled to the South Pole four times, staying for a couple of months on each visit. He was there at the start of the project, standing on top of the giant crate with a drill to open it and again three years later, in January 2013, to take the telescope off the mount, "warm it up, unplug it, and say goodbye," he says. In this video from 2012, Kaufman takes blogger Jeffrey Donenfeld for a tour of the site.

Antarctica is plenty cold, but the CMB is colder still. It's 2.7 Kelvin, just a few degrees above absolute zero. To register the signal, a cryogenic system chilled the detectors even more, to 250 millikelvin, "mind numbingly, interestingly cold," Kaufman says.

Kaufman says he's thrilled to have had a part in this fundamental discovery. "This is the kind of result you dream about when you start to work a project like this."

Last modified: 03/26/2014

Wired Magazine: How the Biggest Scientific Discovery of the Year Was Kept a Secret

news picture Great surprises in science don't just happen-they're engineered.

When researchers announced earlier this week that they might have made what is essentially the scientific breakthrough of the year-echoes from the earliest fraction of a second after the Big Bang known as primordial B-mode polarizations-it seemed to come out of left field. Similarly large announcements, like the discovery of the Higgs boson, generally have followed months of speculation, rumors, and even leaks.

Full Story:

Last modified: 03/25/2014

Scientists see 'fingerprint' of Big Bang

news picture UCSD Physicist Brian Keating and scientists at four other universities announced they've found circumstantial evidence of the spark that caused the Big Bang 13.78 billion years ago.

A long held belief by scientists that the universe began to rapidly expand at the dawn of time may have been confirmed by a telescope that UC San Diego helped build at the South Pole to study the earliest moments of the cosmos.

The Harvard-Smithsonian Center for Astrophysics announced Monday that the BICEP 2 telescope might have detected the aftermath of the "cosmic inflation" that they think occurred just after the universe arose 13.8 billion years ago in the so-called Big Bang.

This period of inflation appears to have generated waves of gravity that left a swirl-like imprint on light from the Big Bang. The telescope saw those swirls in what could be an important clue about how the universe started.

Full Article: U-T San Diego

Story Updates:

Interview with Brian Keating


Graphic on POLARBEAR and Simons Array::

Last modified: 03/25/2014

UC San Diego Physics Department ranked #16 by US News and World Report

news picture The 2015 edition of the U.S. News & World Report's Best Graduate Schools guidebook, released today, highly ranks the University of California, San Diegoss professional schools in engineering and medicine, as well as its academic Ph.D. programs in the sciences.

The U.S. News guidebook annually ranks professional school programs in business, education, engineering, law and medicine. Beyond the five disciplines ranked annually, the publication also periodically ranks programs in other areas. This year, the guidebook released new rankings for Ph.D. programs in the sciences including biological sciences, chemistry, computer science, earth sciences, mathematics and physics in which UC San Diego earned top marks.

""These new rankings confirm UC San Diego's excellence in education and research," said Chancellor Pradeep K. Khosla. "UC San Diego's strong academic programs across diverse disciplines give students the opportunity to work closely with our award-winning faculty to pursue endless opportunities for personal and intellectual development."

"The data from U.S. News indicates UC San Diego graduate programs in the sciences are among the best in the nation. Biological sciences (14th), chemistry (21st), computer science (15th), earth sciences (16th), mathematics (23rd), and physics (16th) were listed near the top nationally in their overall fields. U.S. News also gave high marks to specialties in discrete mathematics and combinations (3rd), and neuroscience/neurobiology (2nd)."

Last modified: 03/13/2014

UCSD Ph.D student Darcy Barron: TV hash could signal evidence for the Big Bang

news picture The snow-like hash on an analogue television is caused by background radiation from the Big Bang, the explosion 13.8 billion years ago which led to the formation of the Universe. But the Big Bang and the inflation of the universe which followed is presently just a theory. Darcy Barron's work has the potential to produce evidence which would turn theory into fact.

Complete Article: The Science Show

Last modified: 03/10/2014

Ilya Valmianski selected as the 2014 recipient of the Inamori Fellowship

news picture I am delighted to announce that Mr. Ilya Valmianski has been selected as the 2014 recipient of the Inamori Fellowship representing the Department of Physics. Inamori Fellowships are awarded annually to one or two of our best and brightest graduate students who are expected to contribute to the future of humanity through a balance of scientific progress and the human spirit.

Mr. Valmianski has been working with Professor Ivan Schuller for over two years during which he has quickly developed extensive skills in thin film and nanodevice fabrication, electron beam and photolithography, as well as numerous characterization techniques. Ilya is friendly and helpful to his colleagues and has shown himself as a good team member and a confident leader. He has collaborated extensively with other research groups in the US and abroad. He has a good background in both physical sciences and humanities, which gives him an understanding of the mutual dichotomy of human knowledge. Before joining Professor Schuller's laboratory, Ilya had done research and published in biophysics, neuroscience, and fusion science technology. His multifaceted research experience is intertwined with his love for philosophy, history, and art. An American citizen, born in the Soviet Union, gives him a unique perspective on international interactions. His scientific knowledge, intelligence and leadership qualities allow him to successfully work to "ensure the future of humanity through the balance of the scientific process and the human spirit."

On behalf of the Department, I congratulate Mr. Valmianski for being awarded this prestigious honor.

Dimitri Basov
Chair, Department of Physics

Last modified: 02/28/2014

John McGreevy promoted to Associate Professor

news picture I am pleased to announce that John McGreevy has been promoted to the rank of Associate Professor with tenure in the Department of Physics. On behalf of the department, I congratulate John on this important milestone in his career and wish his continued success in teaching and research in the future.

Dimitri Basov

Dimitri N. Basov
Chair, Department of Physics

Last modified: 02/28/2014

Massive weather systems revealed in study of the nearest brown dwarfs

news picture Adam Burgasser reported the results of an international monitoring campaign targeting the nearest brown dwarfs, during a press conference at the 223rd Meeting of the American Astronomical Society. Prof. Burgasser's collaboration made spectral and photometric measurements of the Luhman 16AB system, and L dwarf and T dwarf pair, using a dozen telescopes on four continents. The reported measurements, based on just two telescopes, allowed the team to constrain the size and variation of storm cells in mineral and metal clouds in the atmosphere of one of the brown dwarfs, which is only 6.5 light-years from the Sun. Read More

Last modified: 01/24/2014

Source of Moon Curse Revealed by Eclipse

news picture Strange events have long been linked to nights of a full moon, though careful scrutiny dispels any association. So, when signals bounced off the lunar surface returned surprisingly faint echoes on full moon nights, scientists sought an explanation in reason rather than superstition. Still, the most compelling evidence arrived during another event that once evoked irrational fears-on a night when Earth's shadow eclipsed the full moon.

Tom Murphy, a physicist at UC San Diego, is among the scientists who have aimed laser beams at suitcase-sized reflectors placed on the moon by Apollo astronauts and unmanned Soviet rovers. By precisely timing the light's return to Earth, Murphy can measure the distance from here to the moon with millimeter precision.

Full Story: http://ucsdnews.ucsd.edu/feature/source_of_moon_curse_revealed_by_eclipse?utm_campaign=thisweek&utm_medium=web&utm_source=tw--web

Last modified: 02/10/2014

Sequencing by quantum tunneling approach has now been demonstrated

news picture UCSD Physics Professor Max Di Ventra's sequencing by tunneling approach has now been demonstrated by the Japanese company Quantum Biosystems. The tunneling effect, or quantum tunneling, is a phenomenon whereby a microscopic particle uses quantum effects to "tunnel through" a potential energy barrier. Di Ventra has suggested to use this phenomenon to differentiate the different DNA bases and extract the sequence information. Quantum Biosystems has released the first reads of DNA using a new low-cost chip that interrogates single-stranded DNA based on this idea.

This new technology offers low-cost, label-free, high-throughput sequencing of DNA, RNA and proteins for personalized medicine.

Find out more about Quantum Biosystems and the technique at: http://www.quantumbiosystems.com

Last modified: 01/31/2014

Galaxies on FIRE: Star feedback results in less massive galaxies

news picture Dusan Keres and collaborators convincingly show that large amount of energy released by individual stars has dramatic consequences for the evolution of galaxies. For a long time astrophysicists attempted to understand why galaxies contain only a small fraction of the material available in the universe.

In a new set of realistic supercomputer models of galaxies in our universe called FIRE (The Feedback in Realistic Environments) multi-university collaboration convincingly showed that this lack of cosmic material in galaxies is related to energetic events that closely follow formation of stars. Energy released by individual young stars substantially affects the evolution of galaxies and pushes large quantities of galactic gas into the inter-galactic medium preventing its accumulation in galaxies. (Link to press release from Caltech: http://www.caltech.edu/content/galaxies-fire-star-feedback-results-less-massive-galaxies).

Read More: http://www.sciencedaily.com

Last modified: 01/30/2014

UCSD Physics Professor Adam Burgasser 2013 UCSD EO/AA Diversity Award recipient

news picture The Chancellor of UCSD has announced that Adam Burgasser, Associate Professor of Physics and member of CASS, has been awarded the 2013 Equal Opportunity/Affirmative Action and Diversity Award. This award is given to individuals, departments, and organizational units who have made outstanding efforts to further diversity, equal opportunity, and affirmative action at UCSD. We in CASS are very familiar with Adam's extensive outreach/diversity efforts and are grateful for his leadership on these issues. This award was richly deserved. Congratulations Adam.

Last modified: 01/30/2014

"What we're trying to do is essentially detect the Big Bang itself"

news picture The Simons Foundation has awarded co-investigators Brian Keating and Adrian Lee $4.3 million to build two additional telescopes, and implement improvements to the existing device. Together, the three telescopes will be known as the Simons Array.

The origin of the universe is one of the greatest scientific mysteries of our time. And proof of inflation - the hypothesized moment following the Big Bang, when the universe expanded exponentially - has become a highly pursued line of study.

"What we're trying to do is essentially detect the Big Bang itself," says Keating. "To discover the conditions at the exact instant the universe originated."

If inflation did in fact occur, researchers theorize that it would have left ripples in spacetime known as gravitational waves. These waves, in turn, would have left behind signatures of polarized light called primordial B-modes. The Simons Array, when complete, will provide a clearer and more accurate view of these primordial B-modes.

Full article available here: https://www.simonsfoundation.org/features/foundation-news/new-telescopes-search-for-origin-of-universe/

Last modified: 01/16/2014

Kalli Kappel - Physics Major - 2013 recipient of the Selma and Robert Silagi Award for Undergraduate Excellence

news picture This annual award of $5,000 honors the top graduating undergraduate in the Divisions of Physical and Biological Sciences, which in addition to Biology includes the Departments of Chemistry and Biochemistry, Mathematics, and Physics.

The Dr. Selma Silagi Award was endowed in memory of Dr. Silagi by her husband, Robert Silagi, son, Daniel J. Silagi, daughter, Laura R. Silagi, and grandson, Simeon S. Weinraub. After Mr. Silagi passed away in 2004, the family asked that the award honor both Selma and Robert. Selma Epstein Silagi was an outstanding student at every level, graduating with honors from Hunter College. She went on to graduate study in zoology at Columbia University, receiving her Master's Degree in 1938. After 22 years of service as a biology teacher in New York City, Dr. Silagi returned to graduate studies at Columbia University where she received a Ph.D. in genetics in 1961. Dr. Silagi subsequently took a faculty position at Cornell University Medical School where, in 1966, she used a mouse model to change malignant melanoma cells into non-malignant cells and back again. This seminal work, which stimulated basic cancer research; was published in the 1970 Proceedings of the National Academy of Sciences. In 1973, Dr. Silagi was the only woman scientist invited to join twenty other internationally known scientists at the Princess Takamatsu International Cancer Symposium in Tokyo. Dr. Silagi's passion for excellence in scientific research never wavered. She passed away in 1998.

Congratulations on your commitment and dedication to learning and research.

Last modified: 12/19/2013

Leading Nanoscience Experts Meet on Easter Island

news picture CCTV's Stephen Gibbs reports on a conference that took place on Easter Island for some of the world's leading experts in nanoscience, concerned with examining matter around the scale of single atoms. Easter Island Conference Video

Last modified: 09/16/2013

Quark asymmetries hint at physics beyond the Standard Model

news picture (Phys.org) --While scientists have become increasingly convinced that the Standard Model of particle physics is incomplete, it's still unclear exactly how the Standard Model needs to be extended. Experiments have shown that the Standard Model cannot explain certain top quark observations, but a variety of extensions of the Standard Model have been proposed to explain them, and it's unclear which extension is correct. In a new paper published in Physical Review Letters, physicists Benjamin Grinstein and Christopher W. Murphy at the University of California, San Diego, have explained how upcoming data on the bottom quark can be used to distinguish between competing new physics explanations of unexpected top quark data.

"There has been much excitement the last couple of years precipitated by reports by the two experimental collaborations working at the Tevatron (at Fermilab, outside Chicago) that a much larger-than-expected top-quark forward-backward asymmetry is seen," Grinstein told Phys.org. "Several models have been proposed to explain this unexpected result. Our paper suggests a way to distinguish among the various models that have been proposed, since these models give very different bottom-quark forward-backward asymmetries. When a sufficiently precise measurement of the bottom-quark forward-backward asymmetry is performed, we will be able to narrow down significantly the new physics that the Tevatron experiments seem to have uncovered.

"But perhaps more importantly, observations of the bottom-quark forward-backward asymmetry in disagreement with expectations from the Standard Model, when put together with the top-quark forward-backward asymmetry, would demonstrate fairly conclusively that there is new physics in the form of new particles and interactions not included in the Standard Model, and would point the way toward its direct experimental confirmation. So, as you can see, this would go to the heart of the question in particle physics."

As the physicists explain, a quark's forward-backward asymmetry refers to the likelihood that the quark is moving in the forward or backward direction after it is produced in a proton-antiproton collision.

"The Tevatron is a large circular particle accelerator in which protons and antiprotons travel in opposite directions," Murphy said. "The direction of travel of a proton at the point it collides with an antiproton is called the 'forward' direction. Often a b-quark and an anti-b-quark are produced as a result of the proton-antiproton collision. There are several ways to define a 'bottom-quark forward-backward asymmetry,' but they all are a measure of how more (or less) likely it is for the produced b-quark to be moving preferentially in the forward direction. For example, one may count the number of collisions with a forward-moving b-quark, subtract the number of collisions with a backwards-moving b-quark, and divide this by the total number of collisions that produce b-quarks. It should be noted that the asymmetry is not just a single number because it can be determined for various values of the energies of the produced b-quarks. So in fact the asymmetry is a function of the energy of the b-quarks."

This is the second plot showing the predicted bottom-quark forward-backward asymmetry (in percentage) plotted against the energy (in GeV units) of the bottom quark-antiquark pair produced in the proton-antiproton collision at the Tevatron. ...more If new physics is involved, as the physicists expect, then the bottom-quark forward-backward asymmetry might be larger than predicted by the Standard Model, or the asymmetry may even be reversed.

"The Standard Model of electroweak and strong interactions predicts a very small bottom-quark forward-backward asymmetry at the Tevatron, of the order of a few percent," Grinstein said. "What we have shown in our work is that new physics can change this number dramatically. One of the interesting features we discovered is that when the energy of the b-quark and b-antiquark sum to the rest energy of the Z-boson (one of the particles responsible for weak interactions), the asymmetry is enhanced. We furthermore showed that, at this particular energy, the effects of new physics can be greatly amplified. For example, in one popular class of models the sign of the asymmetry is reversed, relative to that predicted by the Standard Model, in the energy region corresponding to the Z-boson's rest energy."

The plots in the physicists' paper tell a more detailed story of the possibilities for new physics. The two plots included here show the predicted bottom-quark forward-backward asymmetry (in percentage) plotted against the energy (in GeV units) of the bottom quark-antiquark pair produced in the proton-antiproton collision at the Tevatron.

In both plots, the orange line represents the Standard Model prediction, while the other colors correspond to predictions from proposed extensions of the Standard Model. The plots are not continuous, but instead they are bar graphs in which the quark pairs of energies in given "bins" are collected together. The black vertical bars indicate what the CDF experiment at Fermilab predicts as its sensitivity, meaning they will be able to distinguish between colored lines that are separated by more than the size of the black bar.

Last modified: 08/27/2013

Growth Laws Call Shots

news picture Synthetic Biology: Linear relationships explain cell response during fermentation

Cells obey simple "growth laws" that describe linear relationships between cell growth and protein expression, Terence T. Hwa and colleagues at the University of California, San Diego, report (Science, DOI: 10.1126/science.1192588). Their findings could ease the ability to predict cell growth in synthetic biology experiments, fermentation processes, and other areas.

"Hwa and colleagues have used an integrated computational and experimental approach to show that protein expression influences cell growth and vice versa," says James J. Collins, who studies synthetic biology at Boston University. "That's important because efforts in synthetic biology assume that synthetic circuits and other constructs are in most cases isolated and independent of other actions in cells."

The researchers changed the state of Escherichia coli cells by inhibiting their ribosomes, which tends to suppress protein expression, or by varying their nutrient levels. They found that when the growth rate increases by boosting nutrients, the ribosome content of cells likewise increases linearly, increasing protein expression. Another linear relationship they found was that "when you slow down the ribosome, the cell makes more ribosome and less of other proteins," Hwa notes.

On the basis of these growth laws, they divided the bacterium's proteome into three broad categories: ribosomal, metabolic, and housekeeping. Housekeeping proteins, which account for about 50% of the proteome, don't change with growth state, but the cell varies in the other two categories, depending on growth conditions.

"The rule is extremely simple," Hwa says. "If you have poor nutrients, then you devote more resources to the metabolic portion. If your ribosome is having trouble translating, you devote more resources to the ribosomes.

The findings also help explain why engineered pathways in bacteria slow down cell growth: Because "unnecessary" proteins produced by engineered genes reduce the production of both metabolic and ribosomal portions of the proteome. "We predicted that the growth rate would drop linearly with the amount of these unnecessary proteins in the cell," Hwa says. They found that growth slowed down just as predicted when engineered E. coli expressed ß-galactosidase in large quantities.

"The authors have shown that the cell cycle itself, and the general growth state of the cell, plays a big role in the output of your circuit," Collins says.

Chemical & Engineering News
ISSN 0009-2347
Copyright © 2013 American Chemical Society

Last modified: 07/23/2013

Understanding drug-resistant bacteria

news picture UC San Diego scientists explore role of varying drug levels in speeding bacterial emergence.

Strains of bacteria able to resist multiple antibiotics pose a growing threat to public health, yet the means by which resistance quickly emerges aren't well understood.

Scientists led by physics professor Terence Hwa at the University of California, San Diego, thought that the variety of environments in which bacteria encounter antibiotic drugs could play an important role. They have developed a mathematical model, published in the June 18 early online edition of the Proceedings of the National Academy of Sciences, that demonstrates how that would work.

Drug levels can vary widely between different organs and tissues in the human body, or between different individuals in a hospital. To account for that, their model considers a matrix of "compartments" with differing concentrations of a drug.

The bacteria in their model can move randomly from one compartment to the next. Their survival and rates of proliferation depend on the concentration of antibiotic within each compartment. And mutations that allow the bacteria to survive and thrive in environments with slightly higher concentrations were allowed to emerge randomly as well.

The system, designed to represent the varying environment of the human body, showed that drug-resistant mutants could evade competition by invading parts of the body, compartments in the model, with slightly higher drug concentrations where other bacteria fail to thrive.

When the process is repeated, the bacterial population can quickly adapt to components with much higher drug concentrations, with adaptation rates that would be very unlikely impossible in a uniform environment.

Although Hwa's team created this model to study the evolution of antibiotic resistance, its formulation quite general. It could be applied to any example of adaptive expansion of an organism's range, a general feature of biological systems that has allowed living things to populate every corner of the Earth, they write.

"Our mathematical model quantifies hypotheses, makes falsifiable predictions and suggests experiments on this vast subject in which many words have been said but few quantitative statements can be found," Hwa said. "The next step is quantitative experimentations which are being carried out in our lab and elsewhere."

The iteration of quantitative prediction, experimental characterization and model refinement characterizes quantitative biology, an emerging discipline that aims to fundamentally change biological research from discipline that is descriptive in nature to one that is quantitative and predictive. prerequisite for engineering and synthesis that promise to be the fruit of this century of biology.

Co-authors include postdoc Rutger Hermsen and graduate student Barret Deris, both members of Hwa's research group. This work was supported by the Center for Theoretical Biological Physics (National Science Foundation) and the National Cancer Institute's Physical Science-Oncology program. Deris holds a National Science Foundation Research Fellowship.

Last modified: 07/23/2013

Physics and Quantitative Biology: identifying a simple genetic circuit for stripes

news picture Many living things have stripes, but the developmental processes that create these and other patterns are complex and difficult to untangle.

Now a team of scientists has designed a simple genetic circuit that creates a striped pattern that they can control by tweaking a single gene.

With multiple starting points, bacteria guided by a simple genetic circuit can create intricate patterns.
"The essential components can be buried in a complex physiological context," said Terence Hwa, a professor of physics at the University of California, San Diego, and one of the leaders of the study published October 14 in Science. "Natural systems make all kinds of wonderful patterns, but the problem is you never know what's really controlling it."

With genes taken from one species of bacterium and inserted into another, Hwa and colleagues from the University of Hong Kong assembled a genetic loop from two linked modules that senses how crowded a group of cells has become and responds by controlling their movements.

One of the modules secretes a chemical signal called acyl-homoserine lactone (AHL). As the bacterial colony grows, AHL floods the accumulating cells, causing them to tumble in place rather than swim. Stuck in the agar of their dish, they pile up.

Because AHL doesn't diffuse very far, a few cells escape and swim away to begin the process again.

Left to grow overnight, the cells create a target-like pattern of concentric rings of crowded and dispersed bacterial cells. By tweaking just one gene that limits how fast and far cells can swim, the researchers were able to control the number of rings the bacteria made. They can also manipulate the pattern by modifying how long AHL lasts before it degrades.

A colony of bacteria with a "synthetic" genetic circuit develops a pattern of strips over 24 hours.
Although individual bacteria are single cells, as colonies they can act like a multicellular organism, sending and receiving signals to coordinate the growth and other functions of the colony. That means fundamental rules that govern the development of these patterns could well apply to critical steps in the development of other organisms.

To uncover these fundamental rules, Hwa and colleagues characterized the performance of their synthetic genetic circuit in two ways.

First, they precisely measured both the activity of individual genes in the circuit throughout the tumble-and-swim cycle. Then they derived a mathematical equation that describes the probability of cells flipping between swim and tumble motions.

Additional equations describe other aspects of the system, such as the dynamics of the synthesis, diffusion and deactivation of one of the cell-to-cell chemical signal AHL.

This three-pronged approach of "wet-lab" experiments, precise measurements of the results, and mathematical modeling of the system, characterize the emerging discipline of quantitative biology, Hwa said. "This is a prototype, a model of the kind of biology we want to do."

Last modified: 07/23/2013

UCSD Physics Graduate Student Yuliya Kuznetsova selected as Intel Fellowship recipient

news picture Yuliya Kuznetsova, a UCSD Physics graduate student who is currently a part of Leonid Butov's group, has recently been selected as a 2013 Intel PhD Fellowship recipient.

The Intel PhD Fellowship Program awards fellowships to exceptional PhD candidates pursuing leading-edge innovation in fields related to Intel's business and research interests. This is a prestigious and highly competitive program with a limited number of fellowships awarded annually. This is an extremely coveted award and selected students are recognized as being amongst the best in their areas of research.

For more information, check out the Intel Fellowships web page.

Last modified: 07/17/2013

UCSD Physics Graduate Student Jason Leonard named ARCS Scholar

news picture Jason Leonard, a UCSD Physics graduate student who is currently a part of Leonid Butov's group, has recently been named an Achievement Reward for College Scientists (ARCS) Scholar.

ARCS Foundation was founded in 1958 to address what was recognized as the critical future and growing need for U.S. scientists and engineers. Toward our goal of advancing science in America, ARCS Foundation invests in outstanding U.S. scholars completing degrees in science, engineering and medical research.

For more information, check out the ARCS Foundation web page.

Last modified: 07/17/2013

Three Generations of UC San Diego Physicists Plumb the Microvasculature of the Mammalian Brain

news picture Blood vessels within a sensory area of the mammalian brain loop and connect in unexpected ways, a new map created by a team that includes three generations of UC San Diego physicists has revealed.

David Kleinfeld (Ph.D. '84), professor of physics and neurobiology at UC San Diego, and colleagues mapped blood vessels in an area of the mouse brain that receives sensory signals from the whiskers.The study, published June 9 in the early online edition of Nature Neuroscience, describes vascular architecture within a well-known region of the cerebral cortex and explores what that structure means for functional imaging of the brain and the onset of a kind of dementia.

The brain area is part of the cerebral cortex, which is fed by small arteries that plunge from the surface of the brain and is drained by small veins that return from the depths to the surface. The network of capillaries in between was uncharted though these tiny vessels deliver crucial oxygen and nutrients to energy-hungry brain cells and carry away wastes.

The team traced this fine network by filling the vessels with a fluorescent gel. Then, using an automated system, developed by co-author Philbert Tsai (B.S. '94, Ph.D. '04), a project scientist in physics, reconstructed the three-dimensional network of tiny vessels. The system, which removes thin layers of tissue with a laser while capturing a series of images, will be instrumental to the rapid mapping planned by the recently announced BRAIN initiative.

This project focused on a region of the cerebral cortex in which the nerve cells are so well known they can be traced to individual whiskers. These neurons cluster in "barrels," one per whisker, a pattern of organization seen in other sensory areas as well.

The scientists expected each whisker barrel to match up with its own discrete blood supply, but that was not the case.

"This was a surprise, because the blood vessels develop in tandem with neural tissue," Kleinfeld said. Instead, microvessels beneath the surface loop and connect in patterns that don't obviously correspond to the barrels.

To search for hidden patterns, they turned to a branch of mathematics called graph theory, which describes systems as connecting paths. Using this approach, led by Harry Suhl, professor emeritus of physics and a founding faculty member who joined the campus in 1961, they determined that the mesh indeed forms a continous network they call the "angiome."

The vascular maps traced in this study raise a question of what we're actually seeing in a widely used kind of brain imaging called functional MRI, which in one form measures brain activity by recording changes in oxygen levels in the blood. The idea is that activity will locally deplete oxygen. But without a discrete blood supply, they wondered how precisely that optical signal would match the sites of neural activity.

To find out, they wiggled whiskers on individual mice and found that optical signals associated with depleted oxygen indeed centered on the barrels, where electrical recordings confirmed neural activity.

The researchers also went a step further to calculate patterns of blood flow based on the diameters and connections of the vessels and asked how this would change if a feeder arteriole were blocked. The map allowed them to identify "perfusion domains," which predict the volumes of lesions that result when a clot occludes a vessel. Critically, they were able to build a physical model of how these lesions form, as may occur in cases of human vascular dementia.

Additional co-authors include Pablo Blinder, John Kaufhold and Per Knutsen. This work was funded by the National Institutes of Health, including a Director's Pioneer Award to Kleinfeld.

Last modified: 06/27/2013

UCSD Physicist Sunil Sinha and his group have publication featured as cover story on Physical Review Letters

news picture Professor Sinha, S.-W. Chen, H. Guo, K. A. Seu, K. Dumesnil, S. Roy authored "Jamming Behavior in a Magnetic System"

One of the most satisfying aspects of condensed matter physics is that a variety of condensed matter systems show universal behavior, i.e. behavior that appears to be common to a wide variety of unrelated systems. A jamming transition occurs when the density of particles becomes large enough and the motion of the particles is restricted by the surrounding particles (think traffic jams!). In this regime, the particles cannot fluctuate freely but move collectively via long range interactions. Examples are colloidal gels or polymer emulsions. Recent work carried out in the Sinha group (S.-W. Chen, H. Guo, K. A. Seu, K. Dumesnil, S. Roy, and S. K. Sinha, Physical Review Letters 110, 217201 (2013) ) using X-ray scattering show that magnetic domains in an antiferromagnet have dynamical behavior very similar to that exhibited by several other jammed systems. The magnetic spins in the rare earth element dysprosium undergo a phase transition from a disordered state to a spiral ordered structure at a temperature of 180 K. When the temperature is slightly above the phase transition temperature, the spins start to form clusters which eventually become magnetic domains below the transition temperature. These domains are head to head with each other and the domain walls form a disordered network, which mimics the jammed state in a soft matter system. As the temperature is further lowered, the sizes of the domains increase and eventually the dynamics are kinetically arrested, as happens when a material becomes a glass.

Abstract: http://prl.aps.org/abstract/PRL/v110/i21/e217201

Last modified: 05/24/2013

Scientists to explore from Arctic to jungles

news picture Passports will take a beating this summer among the county's huge scientific research community.

Scholars from San Diego State University to the University of California San Diego to California State University San Marcos are preparing to travel the globe. They will explore subjects as varied as water quality in Uganda to tuberculosis in Brazil to religious issues in Germany.

We've pulled together a sample of the research, some of which will be explained in greater depth this summer in dispatches sent to U-T San Diego by the scientists.

TOM ROCKWELL, seismologist, San Diego State University, will dig trenches on the Sudetic marginal fault in the Czech Republic in early July. He's examining whether the fault is active and could produce future earthquakes, which may have implications for nuclear power plants in Poland.

BIANCA MOTHE, biologist, Cal State San Marcos, will spend much of the spring and summer in Rio de Janeiro, Brazil, studying immune-system responses in patients who are infected with multi-drug and extreme-drug resistant tuberculosis.

DAN CAYAN, research meteorologist, Scripps Institution of Oceanography in La Jolla, will travel to the Sierra Nevada and the White Mountains in June to explore climate change and variability.

BRIAN KEATING, astrophysicist, UC San Diego, will visit Chile's Atacama Desert in September to study the cosmos from the university's James Ax Observatory, home of the POLARBEAR telescope.

DREW TALLEY, biological oceanographer, University of San Diego, will spend part of June in Bahia San Quintin, Baja California, comparing bivalve populations to historic records from the 1960s

FOREST ROWHER, microbial ecologist, San Diego State, will be diving in the Galapagos, Franz Josef Land (Arctic) and Line Islands in the central Pacific throughout the summer. He will study how human activities increase microbes in the world's oceans.

GENO PAWLAK, mechanical engineer, UC San Diego, will spend part of August and September on the leeward side of Oahu, Hawaii to help improve computerized models that simulate how currents and waves behave when they encounter coral reefs.

MARC MEYERS, materials scientist, UC San Diego, will spend part of August on the Roosevelt River in Brazil trying to obtain the scales of armored catfish, as well as a different fish whose teeth look almost human-like. The goal is to find inspiration for the design of new, better, lighter, tougher and stronger manmade materials.

GEORGE VOURLITIS, ecologist, Cal State San Marcos, will spend part of June and July in Cuiaba, Mato Grosso, Brazil, with undergraduates examining soil fertility and biodiversity in the Brazilian savannah, the country's second-largest and most vulnerable ecosystem.

BETH O'SHEA, geochemist, University of San Diego, will spend part of June at the European Synchrotron Radiation Facility in Grenoble, France, studying how arsenic is released from rocks into household well water.

JOHN HAVILAND, linguistic anthropologist, UC San Diego, will spend part of June and July in northeastern Italy analyzing the Rhaeto-Romance language Friulian, and parts of July and August in Chiapas, Mexico, studying a previously unknown sign language in a Tzotzil (Mayan) speaking village.

ANDRE KUNDGEN, mathematician, Cal State San Marcos, will spend June in Copenhagen, Denmark, exploring new directions in the study of graphs on surfaces. He'll work with renowned mathematician Carsten Thomassen.

JULIE JAMESON, biologist, Cal State San Marcos, will visit Manila, Philippines in June to help educators learn better ways to teach science, technology, engineering and mathematics.

ESRA OZYUREK, anthropologist, UC San Diego, will spend July, August and September in Berlin, doing research on Germans who convert to Islam.

PAUL ETZEL, astronomer, San Diego State University, will spent part of the late summer installing the new 50-inch Phillips Claud Telescope on Mt. Laguna. The telescope will greatly improve the university's ability to study deep space.

CAROLYN KURLE, biologist, UC San Diego, will spend the summer working in bays and estuaries in the San Diego area to study how certain pollution from runoff and stream outfalls is becoming incorporated into coastal food webs.

Copyright 2013 The San Diego Union-Tribune, LLC. An MLIM LLC Company. All rights reserved.

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Last modified: 05/06/2013

Extreme Star Formation Reveals a Fleeting Phase of Galactic Evolution

news picture Astronomers have spotted a galaxy that is igniting new stars faster than ever seen before. Measurements from several instruments show that gas in this galaxy is condensing to form stars close to the maximum rate thought possible.

"What is unique about this particular galaxy is that it is forming stars so rapidly with such a tiny supply of gas," said Aleksandar Diamond-Stanic, a fellow at the University of California's Southern California Center for Galaxy Evolution who helped make the discovery. A team of nine astrophysicists recently reported the finding in Astrophysical Journal Letters.

The team of astronomers estimated the amount of gas in the galaxy using the IRAM Plateau de Bure Interferometer, a telescope in the French Alps that detects a light signal associated with hydrogen gas, the fuel of stars. Images from the Hubble Space Telescope show gas concentrated in a zone just a few hundred light years across, yet that gas is condensing and igniting new stars at a rate hundreds of times that of our own Milky Way galaxy.

The distant galaxy, 6 billion light years away, initially popped out of an image captured by a satellite-based NASA instrument called WISE, for Wide-field Infrared Survey Explorer. The image revealed infrared light, an indication of star formation, pouring out of the galaxy.

That rate of star formation combined with the estimate of available fuel indicates an efficiency close to the theoretical maximum, called the Eddington limit.

"This galaxy is like a highly tuned sports car, converting gas to stars at the most efficient rate thought to be possible," said Jim Geach, an astrophysicist at McGill University who led the study.

"We've caught it just before it runs out of gas," adds Diamond-Stanic, a member the research group led by Alison Coil, a physics professor at UC San Diego who also co-authored the report. This rate of star birth is so ferocious that most of the galaxy's gas will be gone in just a few tens of millions of years, a brief episode in the course of its evolution.

That's why they think no galaxy quite like this one has ever been seen before. Once star formation abates, the team expects the galaxy to mature into a steadier state: an ordinary reddish, elliptical galaxy.

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Last modified: 05/06/2013

UCSD Physics Graduate Student Daniel Rey awarded Department of Energy Computational Science Graduate Fellowship

news picture Congratulations on your selection as a US Department of Energy Computational Science Graduate Fellow Daniel.

The Department of Energy Computational Science Graduate Fellowship (DOE CSGF) program provides outstanding benefits and opportunities to students pursuing doctoral degrees in fields of study that use high performance computing to solve complex science and engineering problems.

The program fosters a community of bright, energetic and committed Ph.D. students, alumni, DOE laboratory staff and other scientists who share a common desire to impact the nation while advancing their science. Fellowship students represent diverse scientific and engineering disciplines but the common thread is their use of mathematical and computing techniques for their research.

Funded by the Department of Energy's Office of Science and National Nuclear Security Administration, the DOE CSGF trains scientists to meet U.S. workforce needs and helps to create a nationwide interdisciplinary community.

The specific objectives of the DOE CSGF program are:

To help ensure an adequate supply of scientists and engineers appropriately trained to meet national workforce needs, including those of the DOE, in computational sciences.

To make national DOE laboratories available for practical work experiences for fellows ensuring cross-disciplinary experience in highly productive work teams.

To strengthen collaborative ties between the national academic community and DOE laboratories so that the multidisciplinary nature of the fellowship builds the national community of scientists.

To raise the visibility of careers in the computational sciences and to encourage talented students to pursue such careers, thus building the next generation of leaders in computational science.

Read the 2004 article (updated July 2009), Building a Community of Leaders to find out more about why the DOE CSGF program is important to the nation.

Last modified: 04/30/2013

UCSD Physicist Frank Wuerthwein is using SDSC's Gordon Supercomputer to crunch data sets from almost one billion particle collisions.

news picture Prof. Frank Wuerthwein and his team are helping to define the research agenda for the Large Hadron Collider (LHC) by crunching data sets from almost one billion particle collisions.

See link for details.

Last modified: 04/04/2013

Professor Oleg Shpyrko has been promoted to the rank of Associate Professor

news picture Professor Oleg Shpyrko has been promoted to the rank of Associate Professor with tenure in the Department of Physics.

The department congratulates him on this important milestone in his career and wishes him continued success in teaching and research in the future.

Last modified: 03/18/2013

UC San Diego Physicist Vivek Sharma featured in New York Times Article, "Chasing the Higgs Boson"

news picture MEYRIN, Switzerland - Vivek Sharma missed his daughter.

A professor at the University of California, San Diego, Dr. Sharma had to spend months at a time away from home, coordinating a team of physicists at the Large Hadron Collider, here just outside Geneva. But on April 15, 2011, Meera Sharma's 7th birthday, he flew to California for some much-needed family time. "We had a fine birthday, a beautiful day," he recalled.

Then Dr. Sharma was alerted to a blog post. There it was reported that a rival team of physicists had beaten his team to the discovery of the Higgs boson - the long-sought "God particle."

If his rivals were right, it would mean a cascade of Nobel Prizes flowing in the wrong direction and, even more vexingly, that Dr. Sharma and his colleagues had missed one of nature's clues and thus one of its greatest prizes; that the dream of any physicist - to know something that nobody else has ever known - was happening to someone else.

He flew back to Geneva the next day. "My wife was stunned," he recalled.

He would not see them again for months.


Last modified: 03/06/2013

Are invisibility cloaks finally here? UCSD Alumnus David Smith to give talk: Wednesday, February 27th, 2013.

news picture What in the name of Harry Potter is David Smith up to? It's not possible to cloak things the way Harry does in some of his adventures, right? Making something invisible would defy the laws of science.

Well, maybe not.

Smith, who earned a doctorate in physics at the University of California San Diego, is a professor at Duke University, where he's stirring attention with his efforts to cloak things with the use of common materials. Smith doesn't make objects literally disappear. But the materials effectively make small things invisible to microwave energy.

It's trippy research that Smith will discuss on Wednesday, February 27, during a free public lecture at UC San Diego. He'll take to the podium at the Great Hall in the International House at 7 p.m., and explain how cloaking works and explore how it might be used to improve our lives. He gave us a preview of his talk during a recent phone call.

Q: Many people think of Harry Potter's fictional invisibility cloak when the subject of invisibility comes up. Is this the kind of thing you're working on?

A: Harry Potter's magical cloak can seemingly make someone completely invisible to detection, whether they're sitting still or moving around. We're not trying to make people invisible. But we are working on a closely related concept that could help make things like your cellphone and certain electronic systems in automobiles work better and more reliably.

Our experiment involves microwaves, an electromagnetic form of energy. Humans can't see microwaves, but they're there and they can get blocked by objects. For example, if you're sitting in an airport trying to use your cellphone your wireless signal might get blocked by the big column that helps hold up the roof of the terminal. That could disrupt your call, or it could make it hard to do something like call up Netflix on the Internet. We're working on ways to make that column 'invisible' to microwaves. We do that by bending the microwaves around blockages.

Q: How do you do that?

A: We cloak objects with meta-materials. These materials cause the microwaves to go around objects. Think of water flowing in a stream. The water flows around things like rocks. In a similar way, microwaves go around things that would block their movement.

Q: And what are meta-materials?

A: They're basically copper circuits that are placed on things like plastic and Teflon. The copper can be arranged in a pattern that causes microwaves to refract. We want to use meta-materials to cloak things that can become an obstruction. This is becoming increasingly important with things like automobiles because they're taking on more and more electronic systems, from wireless Internet to collision-avoidance sensors. We might be able to cloak the grill on a car to prevent it from blocking the signals that come from the collision-avoidance system.

Q: It sounds like this would have a lot of applications for the military. Does it?

A: Yes. The military uses a lot of antennas and they are putting more and more of them together in smaller spaces. We might be able to cloak one antenna to prevent it from blocking the signal of another.

Read more at http://www.utsandiego.com/news/2013/feb/24/cloak-ucsd-edu/

Talk Details:

Last modified: 02/25/2013

Physics Department Dashen Memorial Lecture: "Fundamental Physics and the LHC: A Progress Report"

news picture The annual Dashen Memorial Lecture will be taking place on Thursday, February 21, 2013 at 4pm in the Garren Auditorium in the Biomedical Sciences Building. An expanded teatime will take place in the BSB Lobby at 3:30pm on the same day.

Guest Speaker Nima Arkani-Hamed from the Institute for Advanced Study will be giving the lecture on "Fundamental Physics and the LHC: A Progress Report". The abstract of the lecture is below.

ABSTRACT: Last July's discovery of a "Higgs-like" particle at the Large Hadron Collider was a triumph for both experiment and theory in fundamental physics. But the Higgs also introduces major conceptual paradoxes that strongly suggest we are missing essential new physical principles. Chief amongst these is the severe "naturalness" or "fine-tuning" problem, which arises in trying to answer a simple question: why is there a macroscopic universe? It has long been thought that this mystery would be solved by new symmetries or dynamics at the distance scales probed by the LHC. If so, what should we make of the absence of obvious signs of new physics at the LHC so far? Are entirely different kinds of explanations possible? And what should we be looking for from the LHC when it restarts in 2015? In this talk, I will summarize this excitingly confusing state of affairs, and discuss what we can hope to learn by 2020.

Last modified: 02/12/2013

New Telescopes to Give UC San Diego Researchers Glimpse of the Beginning of Time

news picture Simons Foundation gives $4.3 million in funding for construction and installation of new telescopes to measure universe at its inception.

Where do we come from? What is the universe made of? Will the universe exist only for a finite time or will it last forever? These are just some of the questions that University of California, San Diego physicists are working to answer in the high desert of northern Chile.

Armed with a massive 3.5 meter (11.5 foot) diameter telescope designed to measure space-time fluctuations produced immediately after the Big Bang, the research team will soon be one step closer to understanding the origin of the universe. The Simons Foundation has recently awarded the team a $4.3 million grant to build and install two more telescopes. Together, the three telescopes will be known as the Simons Array.

"The Simons Array will inform our knowledge of the universe in a completely new way," said Brian Keating, associate professor of Physics at UC San Diego's Center for Astrophysics and Space Sciences. Keating will lead the project with Professor Adrian Lee of UC Berkeley.

Fluctuations in space-time, also known as "gravitational waves," are gravitational perturbations that propagate at the speed of light and can penetrate "through" matter, like an x-ray. The gravitational waves are thought to have imprinted the "primordial soup" of matter and photons that later coalesced to become gases, stars and galaxies-all the structures that we now see. The photons left over from the Big Bang will be captured by the telescopes to give scientists a unique view back to the universe's beginning.

The telescopes of the Simons Array-named in recognition of the grant-will focus light onto more than 20,000 detectors, each of which must be cooled nearly to absolute zero. The result will provide an unmatched combination of sensitivity, frequency coverage and sky coverage.

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Last modified: 01/09/2013

Moon impact site named for UCSD Physicist and first female American astronaut Sally Ride.

news picture One year after their arrival at the moon, NASA's twin Grail spacecraft got a grand sendoff into oblivion, climaxing with a well-orchestrated crash onto a crater's rim. The place where they crashed will be named after Sally Ride, America's first woman in space, who passed away this summer.

Ride was in charge of the Grail mission's MoonKam project, which let students from around the world select targets for the probes' cameras. MIT's Maria Zuber, the mission's principal investigator, announced just after today's double whammy that her team received clearance from NASA to name the crash site after Ride.

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Last modified: 12/18/2012

UCSD Physicist Sunil Sinha has cover article published in the December 2012 edition of Nature Materials Magazine.

news picture Professor Sinha and student Yicong Ma are authors of, "Long-range interlayer alignment of intralayer domains in stacked lipid bilayers" which is featured on the magazine cover for the December 2012 edition.

The article can be read here: October 2012 Nature Materials

Last modified: 12/07/2012

5 UC San Diego Physicists elected as Fellows of American Association for the Advancement of Science.

news picture In October 2012, the AAAS Council elected 701 members as Fellows of AAAS. These individuals will be recognized for their contributions to science and technology at the Fellows Forum to be held on 16 February 2013 during the AAAS Annual Meeting in Boston, Massachusetts. The new Fellows will receive a certificate and a blue and gold rosette as a symbol of their distinguished accomplishments.

Congratulations to Dimiti Basov, Benjamin Grinstein, David Kleinfeld, Aneesh Manohar, Art Wolf.

Last modified: 11/29/2012

UC San Diego Physics Alumni Pens Article for New York Times, "Hiding in Plain Sight"

news picture Imagine yourself at a magic show. The magician brings out a tiger and coaxes it into a large, colorful box on the stage. He closes the lid, says a few mysterious words and then - poof - opens the side panel, revealing the inside of the box to be empty. The tiger is gone. Cue applause.

We know, of course, that tigers are not apt to vanish into thin air; we know that such magic tricks are more trick than magic. But how is it possible that our eyes can be deceived so easily?

The answer has much to do with the way our sense of sight works. As we look around a room, our eyes detect the light that bounces off nearby people or objects, and our brains interpret the images formed from the patterns of light received. We can even figure out what material something is made of based on the way it reflects and transmits light: metal is opaque and typically very reflective; plastic, which is more dull and often translucent, absorbs some of the light and reflects the rest in all directions. Our brains, then, turn these signals from reflections into breathtakingly complex pictures of the world around us. And it all happens faster than the blink of an eye. Indeed, after every blink of an eye.

Such lightning-fast cognitions are possible partly because the brain makes certain automatic assumptions: it figures that light has traveled in a straight line from the object to our eyes. Remarkably, in that built-in assumption is the recipe for a bit of magic that humans (and mythical humans) have sought, from the time of Plato to the age of Harry Potter: invisibility.

The trick involves the ability to bend and distort light as it travels through space - in other words, to make it do what the brain assumes it won't. In some ways, it's the same sleight of hand that the magician uses with the tiger. He uses a mirror angled in such a way that when we think we're looking into an empty box, we're actually seeing the reflection from the bottom of the box and assuming it's the back. Since we don't expect that the light reaching our eyes has swerved, making a 90-degree turn along the way, our eyes "tell" us the tiger has vanished. (In reality, he's hiding comfortably in the box.)

Now we've found a way to one-up this neat trick with science: changing the trajectory of light without using mirrors. We do it with the science of materials - designing a "cloak" that can make light curve around an object, and then emerge just as if it had passed in a straight line through space. (Think of it like water flowing past a rock in a stream.)

The phenomenon is indeed supernatural. That's because nature doesn't appear to offer any materials that can accomplish this feat. The reason is that light has both electric and magnetic components - and to make it swerve around an object, one has to redirect both of these very different components and have them sync up immediately after the detour. That's impossible to do with metals, fabrics or any other traditional materials.

But research findings over the past decade have shown us how to develop artificially structured "metamaterials" - in which tiny electrical circuits serve as the building blocks in much the same way that atoms and molecules provide the structure of natural substances. By changing the geometry and other parameters of those circuits, we can give these materials properties beyond what nature offers, letting us simultaneously manipulate both the electric and magnetic aspects of light in striking harmony.

This year, with one such metamaterial, we built the world's first invisibility cloak capable of managing both components of light.

There is a catch, admittedly. Our cloak works only on microwaves, not on visible light. And humans don't "see" microwaves in the first place, making the idea of invisibility seem, well, a little extraneous.

Still, even if we mortals don't see them, many essential devices do. Nearly every time you walk through security at an airport, your body is scanned with microwaves. Also, your cellphone, iPad and other devices make a similar kind of virtual eye contact with one another. So, even in the microwave realm, cloaking can potentially be used to remove obstacles from the paths of direct microwave communications (or hide things we don't want detected).

More important, microwaves are part of the same electromagnetic spectrum as visible light. In principle, if cloaks can be made to work at microwave frequencies, they might one day be made to work at visible wavelengths.

This will be far more difficult: the wavelengths of visible light are more than 10,000 times smaller than those of microwaves, meaning that the corresponding metamaterials would have to be equally reduced in size.

What excites scientists and Harry Potter fans alike, though, is that our microwave cloak proves there's no theoretical limitation that would prevent someone from building a visible-light cloak.

There are some tricky technological barriers to work out. But in this case, at least, not seeing is believing.

David R. Smith is a professor of electrical and computer engineering at Duke University, where Nathan Landy is a graduate student.


Last modified: 11/17/2012

Intense Bursts of Star Formation Drive Fierce Galactic Winds

news picture Fierce galactic winds powered by an intense burst of star formation may blow gas right out of massive galaxies, shutting down their ability to make new stars.

Sifting through images and data from three telescopes, a team of astronomers found 29 objects with outflowing winds measuring up to 2,500 kilometers per second, an order of magnitude faster than most observed galactic winds.

"They're nearly blowing themselves apart," said Aleksandar Diamond-Stanic, a fellow at the University of California's Southern California Center for Galaxy Evolution, who led the study. "Most galactic winds are more like fountains; the outflowing gas will fall back onto the galaxies. With the high-velocity winds we've observed the outflowing gas will escape the galaxy and never return." Diamond-Stanic and colleagues published their findings in Astrophysical Journal Letters.

The galaxies they observed are a few billion light years away with outflowing winds of 500 to 2,500 kilometers per second. Initially they thought the winds might be coming from quasars, but a closer look revealed these winds emanate from entire galaxies.

Young, bright and compact, these massive galaxies are in the midst of or just completing a period of star formation as intense as anyone has ever observed.

"These galactic-scale crazy-fast winds are probably driven by the really massive stars exploding and pushing out the gas around them," said Alison Coil, professor in UC San Diego's Center for Astrophysics and Space Sciences and a co-author of the paper. "There's just such a high density of those stars it's like all these bombs went off near each other at the same time. Each bomb evacuates the area around it, then the next can push gas out further until they're evacuating gas on the scale of the whole galaxy."

Galaxies with winds this fast are also quite rare, opening up the question of whether these are unusual events or part of a common phase in the evolution of massive galaxies that is seldom observed because it is so brief.

Astrophysicists still lack an explanation for how and why starmaking ends. Theorists who model the evolution of galaxies often invoke supermassive black holes called active galactic nuclei, which can also generate savage winds, to explain how gas needed to form stars can be depleted.

These new observations demonstrate that black holes may not be neccesary to account for how these kinds galaxies run out of gas. "The winds seem to be powered by the starburst," Diamond-Stanic said. "The central supermassive black hole is apparently just a spectator for these massive stellar fireworks."

Last modified: 08/20/2012

Halo of Neutrinos Alters Physics of Exploding Stars.

news picture ScienceDaily (Aug. 20, 2012) -- Sparse halos of neutrinos within the hearts of exploding stars exert a previously unrecognized influence on the physics of the explosion and may alter which elements can be forged by these violent events.

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Last modified: 08/19/2012

Hunt for Higgs reveals new particle.

news picture Physicists have observed a new particle that so far matches the signature they expect from the long-sought Higgs boson. But they have not yet collected enough information about the new particle to confirm that it really is the one they seek.

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Last modified: 07/03/2012

Computing Grid Built for Physics Benefits a Wide Range of Science.

news picture Snaking cables and racks of computer processors with winking blue lights fill a room in University of California, San Diego's Mayer Hall. It's a powerful resource, made more so through links to a network of more than 80 similar centers distributed across the country.

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Last modified: 06/28/2012

Electrons Ripple Across Atom-Thin Layers of Carbon.

news picture With a beam of infrared light, scientists have sent ripples of electrons along the surface of graphene and demonstrated that they can control the length and height of these oscillations, called plasmons, using a simple electrical circuit.

This is the first time anyone has observed plasmons on graphene, sheets of carbon just one atom thick with a host of intriguing physical properties, and an important step toward using plasmons to process and transmit information in spaces too tight to use light.

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Last modified: 06/19/2012

Exotic particles, chilled and trapped, form giant matter wave

news picture Physicists have trapped and cooled exotic particles called excitons so effectively that they condensed and cohered to form a giant matter wave.

This feat will allow scientists to better study the physical properties of excitons, which exist only fleetingly yet offer promising applications as diverse as efficient harvesting of solar energy and ultrafast computing.

"The realization of the exciton condensate in a trap opens the opportunity to study this interesting state. Traps allow control of the condensate, providing a new way to study fundamental properties of light and matter," said Leonid Butov, professor of physics at the University of California, San Diego. A paper reporting his team's success was recently published in the scientific journal Nano Letters.

Excitons are composite particles made up of an electron and a "hole" left by a missing electron in a semiconductor. Created by light, these coupled pairs exist in nature. The formation and dynamics of excitons play a critical role in photosynthesis, for example.

Like other matter, excitons have a dual nature of both particle and wave, in a quantum mechanical view. The waves are usually unsynchronized, but when particles are cooled enough to condense, their waves synchronize and combine to form a giant matter wave, a state that others have observed for atoms.

Scientists can easily create excitons by shining light on a semiconductor, but in order for the excitons to condense they must be chilled before they recombine.

The key to the team's success was to separate the electrons far enough from their holes so that excitons could last long enough for the scientists to cool them into a condensate. They accomplished this by creating structures called "coupled quantum wells" that separate electrons from holes in different layers of alloys made of gallium, arsenic and aluminum.

Then they set an electrostatic trap made by a diamond-shaped electrode and chilled their special semiconducting material in an optical dilution refrigerator to as cold as 50 milli-Kelvin, just a fraction of a degree above absolute zero.

A laser focused on the surface of the material created excitons, which began to accumulate at the bottom of the trap as they cooled. Below 1 Kelvin, the entire cloud of excitons cohered to form a single matter wave, a signature of a state called a Bose-Einstein condensate.

Other scientists have seen whole atoms do this when confined in a trap and cooled, but this is the first time that scientists have seen subatomic particles form coherent matter waves in a trap.

Varying the size and depth of the trap will alter the coherent exciton state, providing this team, and others, the opportunity to study the properties of light and mater in a new way.

This most recent discovery stems from an ongoing collaboration between Leonid Butov's research group in UC San Diego's Division of Physical Sciences, including Alexander High, Jason Leonard and Mikas Remeika, and Micah Hanson and Arthur Gossard in UC Santa Barbara's Materials Department. The Army Research Office and the National Science Foundation funded the experiments, and the Department of Energy supported the development of spectroscopy in the optical dilution refrigerator, the technique used to observe the exciton condensate in a trap.

Last modified: 05/29/2012

UC San Diego Receives $7 Million from DOD for Innovative Neural Research

news picture An interdisciplinary team of scientists at UC San Diego composed of physicists, biologists, chemists, bioengineers and psychologists has received a five-year, $7 million grant from the U.S. Department of Defense to investigate the dynamic principles of collective brain activity.

The innovative research effort, which is being funded by the Office of Naval Research under the Defense Department's MultiUniversity Research Initiative, or MURI, will also involve scientists at UC Berkeley and the University of Chicago.

The team plans to conduct basic research on how collective action in the brain learns, modulates and produces coherent functional neural activity for coordinated behavior of complex systems.

"This research will tie together theoretical ideas, hardware implementation of structural models and experimental investigations of human and animal behavior to develop a quantitative understanding and a predictive language for discussing complex physical and biological systems," said Henry Abarbanel, a physics professor at UC San Diego who is heading the collaboration.

The grant will pay for the costs of new laboratory facilities at UC San Diego and the University Chicago, create powerful parallel computing capabilities for the three universities involved and employ 10 or more postdoctoral research fellows. Key UC San Diego researchers participating in the effort are Katja Lindenberg, professor of chemistry and biochemistry; Tim Gentner, associate professor of psychology; Gert Cauwenberghs, professor of bioengineering; Misha Rabinovich, research physicist in the BioCircuits Institute; and Terry Sejnowski, professor of biology.

This is the fourth MURI award led by Abarbanel. The first focused on theory and experiment in complex fluid flows and was funded by the Defense Advanced Research and Projects Agency from 1988 to 1993. The second investigated chaotic communications strategies from 1998 to 2003 under sponsorship by the Army Research Office. The third developed advanced chemical sensing methodologies using animal olfactory dynamics and was funded by the Office of Naval Research from 2007 to 2012.

Last modified: 05/24/2012

Professors Coil, Dudko and Anderson promoted.

news picture Professor Olga Dudko and Professor Alison Coil have been promoted to the rank of Associate Professor with tenure in the Department of Physics. Dr. Michael Anderson has been promoted to Lecturer with Security of Employment (LSOE). The department congratulates them on this important milestone in their careers and wish them continued success in teaching and research in the future.

Last modified: 05/21/2012

Antarctica Service Medal of the United States of America, authorized by Congress

news picture UCSD physics graduate Student Jonathan Kaufman was recently awarded the Antarctica Service Medal of the United States of America, authorized by Congress in recognition of his contributions to exploration and scientific achievement under the U.S. Antarctic Program. Jonathan Kaufman, working under Prof. Brian Keating, recently completed his third season at the Amundsen-Scott South Pole Station in Antarctica working on the BICEP2 telescope--currently leading the search for evidence of the inflationary expansion of the early universe, believed to have occurred in the fractions of a second immediately after the Big Bang.

Last modified: 04/02/2012

UC San Diego Physicists Find Patterns in New State of Matter

news picture Physicists at the University of California, San Diego have discovered patterns which underlie the properties of a new state of matter. In a paper published in the March 29 issue of the journal Nature, the scientists describe the emergence of "spontaneous coherence," "spin textures" and "phase singularities" when excitons–the bound pairs of electrons and holes that determine the optical properties of semiconductors and enable them to function as novel optoelectronic devices–are cooled to near absolute zero. This cooling leads to the spontaneous production of a new coherent state of matter which the physicists were finally able to measure in great detail in their basement laboratory at UC San Diego at a temperature of only one-tenth of a degree above absolute zero. The discovery of the phenomena that underlie the formation of spontaneous coherence of excitons is certain to produce a better scientific understanding of this new state of matter. It will also add new insights into the quirky quantum properties of matter and, in time, lead to the development of novel computing devices and other commercial applications in the field of optoelectronics where understanding of basic properties of light and matter is needed. Read more at UCSD News Center

Read more at www.physicsorg.com

Read more at www.rdmag.com

Last modified: 03/28/2012

POLARBEAR experiment showing first microwave/radio "vision"

news picture We are proud to announce that we got "first light/microwave" today with the POLARBEAR telescope in the Atacama Desert in Chile. We saw the planets Venus and Jupiter, not in the visible portion of the electromagnetic spectrum, but with microwave/radio "vision".

Doesn't look too exciting at first glance but it's the start of big things for the project and team!

It's an amazing place to be... very much like being an astronaut on Mars due to the high altitude (17,000') and the terrain. To complete the astronaut analogy most of us need to be on supplemental oxygen most of the time, which makes manual labor quite hard. But it sure beats the alternative!

More pictures of POLARBEAR may be located on Flickr, and more detailed information about POLARBEAR may be found at the Huan Tran Telescope web page.

Thanks to the whole collaboration and especially to the UCSD team (Darcy Barron, Dave Boettger, Frederick Matsuda, Nathan Miller, Stephanie Moyerman, Dr. Nathan Stebor, Praween Siritanasak) for all of their hard work and dedication!

Last modified: 01/12/2012

Hints of the Higgs Boson Seen as Trap Set for Elusive Particle Tightens

news picture Physicists announced today that they may have caught glimpses of the Higgs boson, but the signals they see are not yet robust enough to meet the stringent requirements they have set for announcing an official discovery
Read More

Last modified: 12/15/2011

Professor Dudko's PRL publication receives "Editor's suggestion" and is highlighted with a Synopsis on the American Physical Society website

news picture UC San Diego physicist Olga Dudko and her colleagues at the University of Cambridge resolve a central discrepancy between theory and experiment regarding how molecules fold in response to applied forces.

Single-molecule force spectroscopy, which measures how a molecule responds to mechanical forces pulling it apart, is an important tool in the study of biomolecules and other polymers. Experiments have shown that for weak forces molecules end up in two or more states, depending on the amount of stretching, which researchers attribute to how molecules fold and unfold. However, they have found it difficult to close in on a theoretical explanation. One recent study maintains that these experiments monitor a barrierless process, rather than one where the barrier is known to exist. It concluded that what the experiments are actually observing is merely the collapse of the molecules, and not folding per se.

In their paper in Physical Review Letters, Olga Dudko at the University of California, San Diego, and co-workers appear to resolve this gap in our understanding of this fundamental mechanism in biomolecular interactions. From molecular simulation studies of molecular energy surfaces ("energy landscapes"), they find that there is indeed a barrier to folding, and it is this barrier that is probed by the experiments. It is just that the barrier appeared to be absent-hidden, as it were-in the earlier theoretical work, partly because of the method chosen to project a complicated, multidimensional folding scenario onto a single dimension (the "reaction coordinate"). A more robust choice of a folding coordinate ends up revealing the barrier.

This resolution of a central discrepancy between theory and observations in the important field of molecular-particularly protein-folding should bring about a collective sigh of relief among many biological physicists and physical chemists. - Sami Mitra, Physical Review Letters, American Physical Society

Link to the online publication: http://prl.aps.org/abstract/PRL/v107/i20/e208301

Last modified: 11/07/2011

Suspects in the quenching of star formation exonerated

news picture

Supermassive black holes millions to billions times the mass of our Sun lie at the heart of most, maybe all large galaxies. Some of these power brilliantly luminous, rapidly growing objects called active galactic nuclei that gather and condense enormous quantities of dust, gas and stars.

Because astronomers had seen these objects primarily in the oldest, most massive galaxies that glow with the red light of aging stars, many thought active galactic nuclei might help to bring an end to the formation of new stars, though the evidence was always circumstantial.

That idea has now been overturned by a new survey of the sky that found active galactic nuclei in all kinds and sizes of galaxies, including young, blue, star-making factories.

“The misconception was simply due to observational biases in the data,” said Alison Coil, assistant professor of physics at the University of California, San Diego and an author of the new report, which will be published in The Astrophysical Journal.

“Before this study, people found active galactic nuclei predominantly at the centers of the most massive galaxies, which are also the oldest and are making no new stars,” said James Aird, a postdoc at the University of California, San Diego’s Center for Astrophysics and Space Sciences, who led the study.

Black holes, such as those at the centers of active galactic nuclei, can’t be observed directly as not even light escapes their gravitational field. But as material swirls toward the event horizon, before it’s sucked into the void, it releases intense radiation across the electromagnetic spectrum, including visible light. Of these, X-rays are often the brightest as they can penetrate the dust and gas that sometimes obscures other wavelengths.

“When we take into account variations in the strength of the X-ray signal, which can be relatively weak even from extremely fast-growing black holes, we find them over a whole range of galaxies,” Aird said

He searched the sky for X-rays from active galactic nuclei using two orbiting telescopes, the XMM-Newton and the Chandra X-ray Observatory, and compared those signals to a large-scale survey of about 100,000 galaxies that mapped their colors and distances.

Coil led that survey, called PRIMUS, along with colleagues now at New York University and the Harvard College Observatory. Using the twin Magellan telescopes at Las Campanas Observatory in Chile, they detected the faint light of faraway galaxies.

They measured both the color of each galaxy and how much the spectrum of that light had shifted as the galaxies receded in our expanding universe – an estimate of their distance from Earth. Because distances in space reach back in time, they’ve captured nearly two-thirds of the history of the universe in particular segments of the sky.

Galaxies can be distinguished by the color of their light. Younger galaxies glow with the bluish light of young stars. As starmaking ceases, and stars burn through their fuel, the color of their light shifts toward red.

In a sample of about 25,000 of the galaxies from the PRIMUS survey, Aird found 264 X-ray signals emanating from galaxies of every kind: massive and smaller, old elliptical red galaxies and younger blue spirals. They’re everywhere.

So as suspects in the quenching of star formation, active galactic nuclei have been exonerated. And because the astronomers saw similar signals stretching far back into time, they conclude that the physical processes that trigger and fuel active galactic nuclei haven’t changed much in the last half of the universe’s existence.

Yet starmaking has ceased in many galaxies, probably when they ran out of gas, though it’s not clear how that happens. The interstellar gas could all be used up, turned into stars, but Coil studies another possibility: fierce galactic winds that have been seen blowing gas and dust from so-called starburst galaxies.

The source of those winds, and their influence on the evolution of galaxies, is one of Coil’s main areas of current investigation.

Alison Coil is an Alfred P. Sloan Foundation Fellow. The National Science Foundation and NASA provided funding for the PRIMUS survey.

Last modified: 10/07/2011

Simple Math Sheds New Light on a Long-Studied Biological Process

news picture One of the most basic and intensively studied processes in biology--one which has been detailed in biology textbooks for decades--has gained a new level of understanding, thanks to the application of simple math to a problem that scientists never before thought could benefit from mathematics.

The scientists who made the discovery, published in this week's advance online publication of Nature, found that the process bacteria use to quickly adapt to metabolize preferred energy sources such as glucose--a process called "catabolite repression"--is controlled not just by glucose, as had long been known and taught, but just as much by other essential nutrients, such as nitrogen and sulfur, available to bacteria in their growth medium.

"This is one of the most studied processes in molecular biology; it's in every textbook," says Terence Hwa, a professor of physics and biology at UC San Diego, who headed the team of scientists. "We showed that this process doesn't work the way most people thought it did for the past several decades, and its purpose is different from what had generally been assumed."

The basic phenomenon, Hwa says, is analogous to a balanced diet: To reduce an individual's sugar uptake, common wisdom is to reduce the availability of sugar. This strategy backfires on bacteria because they would increase their appetite for sugars -- the process of catabolite repression would direct the bacteria to increase the production of their sugar uptake system to counteract the scarcity of sugar in the environment. However, by figuring out that catabolite repression actually works by sensing the difference between the influx of sugar and that of other essential nutrients such as nitrogen, it is possible to drastically lower the bacteria's appetite for sugar by simply rationing the supply of nitrogen.

Hwa and his team arrived at their surprising finding by employing a new approach called "quantitative biology," in which scientists quantify biological data and discover mathematical patterns, which in turn guide them to develop predictive models of the underlying processes.

"This mode of research, an iterative dialogue between data quantitation and model building, has driven the progress of physics for the past several centuries, starting with Kepler's discovery of the law of planetary motion," explains Hwa. "However, it was long thought that biology is so laden with historical accidents which render the application of quantitative deduction intractable."

The significance of the study, according to Hwa, is that it demonstrates that the physicists' quantitative approach can also effectively probe and elucidate biological processes, even a classic problem that has been heavily scrutinized.

"Molecular biology gives us a collection of parts and interactions," says Hwa. "But how do you make sense of those interactions? You need to examine them in their physiological context. Quantitative patterns in physiological responses, together with mathematical analysis, provide important clues that can reveal the functions of molecular components and interactions, and in this case, also pinpoint the existence of previously unknown interactions."

"It is remarkable that after so many years of studying these cells there are more fascinating things to be discovered by simple experiments and theory," says Krastan B. Blagoev, a program director in the National Science Foundation's Division of Physics, which jointly funded the research with the agency's Molecular and Cellular Biology Division.

Hwa and his team of physicists and biologists at UC San Diego are among the world's leaders in quantitative biology, which is gaining an upsurge of interest and importance in the life sciences. According to a recent National Academy of Sciences report, advances in quantitative biology are a necessary ingredient to ensure our nation continues to make future progress in medicine, genetics and other life science disciplines. By quantifying the complex behavior of living organisms, for example, researchers can develop reliable models that could allow them to more accurately predict processes like drug interactions before untested pharmaceuticals are used in human clinical trials. UC San Diego is in the middle of a major expansion in quantitative biology, with plans to hire 15 to 20 faculty members in this new discipline in different departments over a three-year period.

In their study, the UC San Diego scientists collaborated with colleagues at Peking University in China, the University of Marburg in Germany and the Indiana University of School of Medicine--an international research team formed six years ago with the help of a grant from the Human Frontier Science Program, headquartered in Strasbourg, France.

Biologists have long known that when glucose is the primary carbon source for cells, bacteria such as E. coli repress genes that allow the organism to metabolize other kinds of sugars. This catabolite repression effect is controlled by a small molecule known as "cyclic adenosine monophosphate"--or cAMP.

"Previously, it was thought that glucose uptake sets the cAMP level in the cell," says Hwa. "But we discovered that in reality, it's the difference between carbon uptake and the uptake of other essential nutrients such as nitrogen. So the picture now is very different."

The UC San Diego scientists unraveled this relationship by measuring the level of cAMP and the level of enzymes that break down sugar molecules in bacterial cells against the growth rates of the bacteria, while subjecting these cells to limiting supplies of carbon, nitrogen and other compounds.

"When we plotted our results, our jaws dropped," recalls Hwa. "The levels of the sugar uptake and utilization enzymes lined up remarkably into two crossing lines when plotted with the corresponding growth rates, with the enzyme level increasing upon carbon limitation and decreasing upon nitrogen and sulfur limitation. The enzyme levels followed the simple mathematical rules like a machine." "From the overall pattern, it is clear that there's nothing special about glucose," he adds. "Now we know this process is not about the preference of glucose over other carbon compounds, but rather the fine coordination of carbon uptake in the cell with other minor, but essential nutrient elements such as nitrogen and sulfur."

Hwa points out that the physiological insights derived from simple mathematical relations guided them to figuring out both the strategy and molecular mechanisms their bacteria employ to coordinate carbon metabolism with those of other elements. Such knowledge may be very valuable to the fermentation industry, where metabolic engineers strive to rewire the genetic programs of industrial microorganisms to increase their yield of desirable products, such as insulin for biomedical applications and ethanol for bioenergy.

Hwa further speculates that by similarly quantifying how the human metabolic control system deals with different types of nutrient limitations, one may envision novel strategies to combat diseases such as obesity, which involves an imbalance of macronutrient composition, or even cancer, which requires a full suite of nutrient elements to fuel its rapid growth.

While quantitative biology papers are often filled with complicated mathematical formulas and involved heavy number crunching by computers, Hwa says the mathematics used in this discovery was surprisingly simple.

"We just used line plots," he says. "Our entire study involves just three linear equations. They're the kind of things my 10-year-old daughter should be able to do. Quantitative biology doesn't have to be fancy." Like their mathematical approach, Hwa says his team's experiments were simple enough most of them could have been done 50 years ago. In fact, one prominent scientist was on the right track to discovering the same thing nearly 40 years ago. The Nobel-Prizewinning French scientist Jacques Monod, who was the first to study the effects of catabolite repression quantitatively during World War II 70 years ago and whose study led eventually to the birth of molecular biology 20 years later, wrote a paper published months after his death in 1976 that questioned the standard understanding of catabolite repression--a publication that had been long forgotten until Hwa mentioned his team's results recently to some colleagues from France.

"Monod knew that something was not quite right with the standard picture of cyclic AMP," says Hwa, who was directed to that 1976 paper. "He knew that nitrogen was having an effect on the input and he knew that somehow it was very important."

Hwa says he and his team are now applying the same quantitative approaches to learn more about the response of bacteria to antibiotics and how cells transition from one state to another. "This kind of quantitative, physiological approach is really underutilized in biology," he adds. "Because it's so easy to manipulate molecules, biologists as well as biophysicists tend to jump immediately to a molecular view, often decoupled from the physiological context. Certainly the parts list is important and we could not have gotten to the bottom of our study without all of the molecular work that had been done before. But that in of itself is not enough, because the very same parts can be put to work in different ways to make systems with very different functions."

Other authors of the paper were UC San Diego scientists Conghui You, Hiroyuki Okano, Sheng Hui, Zhongge Zhang, Minsu Kim and Carl Gunderson; Yi-Ping Wang of Peking University in China; Peter Lenz of the University of Marburg in Germany; and Dalai Yan of the Indiana University School of Medicine in Indianapolis.

Last modified: 08/22/2011

Physicist Alexander Schafgans has been named Outstanding Graduate/Professional Student 2011

news picture Alexander Schafgans has been named the Outstanding Graduate/Professional Student for the ways he has enriched the UC San Diego community. The initiative, leadership, talent, and pride that have characterized his time at UC San Diego are noteworthy and a key part of what makes student life at the university vital.

In the fourth year of the Outstanding Graduate/Professional Student Award, eighteen nominations were submitted by students, faculty, and alumni who felt it was important to acknowledge the most talented and gifted graduate/professional students at UC San Diego. With the high quantity of outstanding nominations the awards committee had tremendous difficulty selecting one graduate recipient. However, it was noted that Alexander's stewardship, leadership, and scholarship will continue to make a mark on campus life for future generations of students after graduation.

Vice Chancellor of Student Affairs, Penny Rue comments in her letter to Alexander, "My experience working with students shows that the chance to make a difference is the primary reason you give of yourself, and for that I thank you. Your work on the undergraduate scholarship council is a forecast of what I know will be lifelong involvement at UC San Diego. In addition to receiving this award, you will also receive $1,000 and a lifetime membership to the UC San Diego Alumni Association."

The Outstanding Graduate/Professional Student Award will be presented at the 20 I 1 All Campus Graduation Celebration on Friday, June 10 at 7:00 p.m. on RIMAC field.

Last modified: 01/23/2011

Physics entries win first and second prize in the Faculty/Staff Category and first prize in the Student Category in the Art of Science Competition.

news picture The UC San Diego Science and Engineering Library received 44 amazing images. "We were impressed by the variety, creativity and the scientific story behind each of the entries!"

All of the images will be displayed in the S&E Library beginning Friday, May 27, and continuing through the summer. Please stop by and take a look. They will also be posted on the S&E Flickr page next week.

And the winners are...

Faculty/Staff Category
1st place - Tadel Matevz, Physics
2nd place - Adam Burgasser, Physics
3rd place - David Rideout, Mathematics

Student Category
1st place - Rick Wagner, Physics
2nd place - Christopher Doran, ECE
3rd place - Kim Wright, MAE
Honorable Mention - Alireza Kargar, ECE

ChaOss Begets Order I. (1st place - Tadel Matevz, Physics)

The image shows a Z-boson decaying into electron-positron pair inside the Compact Muon Selenoid (CMS) detector at CERN, European Organization for Nuclear Research in Geneva, Switzerland. The event was produced as a result of lead-lead ion collisions at the Large Hadron Collider and is in fact one of the first events in the world where Z-boson production was observed in heavy-ion collisions. The two opposite, dominant red towers show energy depositions of the electron and positron in the electro-magnetic calorimeter of CMS while other smaller red and blue towers represent the energy deposited by remaining low-energy particles in the electro-magnetic (red) and hadronic (blue) calorimeters of CMS.

Stellar Orbits Dragonfly (2nd place - Adam Burgasser, Physics)

Everything in the Universe moves. Moons, planets, stars, even whole galaxies careen through the cosmos, carrying us along. These motions tell us about the origins of celestial objects, how they have evolved, and the medium of matter, dark matter and dark energy they move through.

In my research, I study our nearest brown dwarf neighbors - very low-mass, low-temperature stars they are a "mere" 10-50 light-years away. These stars orbit our galactic system - the Milky Way Galaxy - along many paths that reveal their diverse ages and origins. The image shows the orbital paths of 200 such brown dwarfs based on data collected from the Two Micron All Sky Survey and the Sloan Digital Sky Survey, projected to show radial and vertical motions. Some of the orbits are clustered, indicating stellar groups that orbit around the Milky Way together; others are very wide, indicating old stars that are just passing through the Solar Neighborhood.

Last modified: 01/23/2011

Professor Adam Burgasser and Professor Congjun Wu Promoted

news picture Professor Adam Burgasser and Professor Congjun Wu have been promoted to the rank of Associate Professor with tenure in the Department of Physics. The department congratulates them on this important milestone in their careers and wish them continued success in teaching and research in the future.

Last modified: 01/23/2011

2011 Ma and Malmberg Award Recipients: Charles Neill and Samuel Stanwyck

news picture This year's Physics Department's recipients of the Shang-keng Ma Memorial Award Endowed by the Shaoyeh Ma Foundation and Malmberg awards are Charles Neill and Samuel Stanwyck. The selection committee, consisting of Professors Fred Driscoll and Clifford Surko, after considerable debate and assessing the students academic achievements selected Sam to receive the John Holmes Malmberg award and Charles to receive the Shang Keng Ma award.

Last modified: 01/23/2011

Professor Ivan Schuller cited as "Notable Alumnus" of Nortwestern University Graduate School

news picture Ivan Schuller, PhD, Physics, 1976: "Schuller's work on artificial metallic superlattices ultimately led to the discovery and application of the phenomena of "giant magentoresistance" in metallic-ferromagnetic conductors, which is the basis of the 'read heads' in modern computer drives"

Last modified: 01/23/2011

UCSD Physicists To Assemble Microwave Telescope in Chile

news picture The assembly of UCSD's telescope will commence shortly now that formal approval from the Chilean government for deployment in Chile's Atacama desert has been received. The telescope is part of the POLARBEAR project seeking to detect evidence for the inflationary epoch of the Big Bang.

Please click on the following link for more information:

Last modified: 01/23/2011

Physicists Build Bigger 'Bottles' of Antimatter to Unlock Nature's Secrets

news picture Once regarded as the stuff of science fiction, antimatter--the mirror image of the ordinary matter in our observable universe--is now the focus of laboratory studies around the world. While physicists routinely produce antimatter with radioisotopes and particle colliders, cooling these antiparticles and containing them for any length of time is another story. Once antimatter comes into contact with ordinary matter it "annihilates"--or disappears in a flash of gamma radiation. Clifford Surko, a professor of physics at UC San Diego who is constructing what he hopes will be the world's largest antimatter container, said physicists have recently developed new methods to make special states of antimatter in which they can create large clouds of antiparticles, compress them and make specially tailored beams for a variety of uses. He described the progress made in this area, including his own efforts, at the annual meeting in Washington, DC, of the American Association for the Advancement of Science.

His talk, "Taming Dirac's Particle," led off the session entitled "Through the Looking Glass: Recent Adventures in Antimatter," at 1:30 pm on February 18. Surko said that since "positrons"--the anti-electrons predicted by English physicist Paul Dirac some 80 years ago-- disappear in a burst of gamma rays whenever they come in contact with ordinary matter, accumulating and storing these antimatter particles is no small feat. But over the past few years, he added, researchers have developed new techniques to store billions of positrons for hours or more and cool them to low temperatures in order to slow their movements so they can be studied. Surko said physicists are now able to slow positrons from radioactive sources to low energy and accumulate and store them for days in specially designed "bottles" that have magnetic and electric fields as walls rather than matter. They have also developed methods to cool them to temperatures as low as that of liquid helium and to compress them to high densities. "One can then carefully push them out of the bottle in a thin stream, a beam, much like squeezing a tube of toothpaste," said Surko, adding that there are a variety of uses for such positrons.

A familiar positron technique that does not use this new technology is the PET scan, also known as Positron Emission Tomography, which is now used routinely to study human metabolic processes and help design new drugs. In the new methods being developed by physicists, beams of positrons will be used in other ways. "These beams provide new ways to study how antiparticles interact or react with ordinary matter," said Surko. "They are very useful, for example, in understanding the properties of material surfaces." Surko and his collaborators at UC San Diego are studying how positrons bind to ordinary matter, such as atoms and molecules. "While these complexes only last a billionth of a second or so," he said, "the 'stickiness' of the positron is an important facet of the chemistry of matter and antimatter." Surko and his colleagues are building the world's largest trap for low-energy positrons in his laboratory at UC San Diego, capable of storing more than a trillion antimatter particles at one time. "We are now working to accumulate trillions of positrons or more in a novel 'multi-cell' trap--an array of magnetic bottles akin to a hotel with many rooms, with each room containing tens of billions of antiparticles," he said.

"These developments are enabling many new studies of nature. Examples include the formation and study of antihydrogen, the antimatter counterpart of hydrogen; the investigation of electron-positron plasmas, similar to those believed to be present at the magnetic poles of neutron stars, using a device now being developed at Columbia University; and the creation of much larger bursts of positrons which could eventually enable the creation of an annihilation gamma ray laser." "An exciting long-term goal of the work is the creation of portable traps for antimatter," added Surko. "This would increase greatly the ability to use and exploit antiparticles in our matter world in situations where radioisotope- or accelerator-based positron sources are inconvenient to arrange." Professor Surko's work is funded by the National Science Foundation, the U.S. Department of Energy and the Defense Threat Reduction Agency.

Last modified: 01/23/2011

Professor Vivek Sharma's talk "Hunting the Higgs" to Premiere on UCSD-TV

news picture UCSD-TV is pleased to announce that Professor Sharma's talk "Hunting the Higgs" will premiere Wednesday, February 23 at 8:00 pm.

The link below includes all scheduled air dates/times, as well as different options to view the program online once it's uploaded to the site just prior to the premiere date. This will include embeddable Flash video and audio and video podcasts.

What Gives Particles Mass? Searching for the Higgs

Last modified: 01/23/2011

New observations of exploding stars

news picture A team led by Bernie Jackson, using the Solar Mass Ejection Imager the team developed, has traced the waxing and waning light of exploding stars more closely than ever before and seen patterns that aren't yet accounted for in our current understanding of how these eruptions occur. Rebekah Hounsell, a graduate student at Liverpool John Moores University in Britain, made the measurements while visiting UCSD.

More information can be found here.

Last modified: 12/10/2010

Tom Murphy - Public Lecture: Einstein, the Moon and the Long Lost Soviet Reflector - THURSDAY (10/28)

news picture Einstein, the Moon and the Long Lost Soviet Reflector

One of the greatest successes of the former Soviet space program was a lunar rover called Lunokhod 1 Russian for "moonwalker." Landing on the moon on November 17, 1970 with a laser reflector, it wandered around the moon's surface for 11 months then mysteriously disappeared -- until last spring.

On April 22, nearly 40 years after Lunokhod 1 disappeared, a team headed by Tom Murphy found the reflector and pinpointed its distance from earth to within one centimeter.

The discovery came as part of a long-term project Murphy heads to send pulses of laser light to the moon from a telescope in New Mexico. The purpose, which he will describe in his talk, is to look for deviations of Einstein's theory of general relativity by measuring the shape of the lunar orbit to within the accuracy of one millimeter, or about the thickness of a paperclip.

The talk is free and the public welcome. Light refreshments will be served afterwards. If you have questions, please contact physcievents@ucsd.edu.

Last modified: 10/21/2010

2010 Dean's Undergraduate Award for Excellence Recipients

news picture It is with great pleasure that we announce the following recipients of the 2010 Physical Sciences Dean's Undergraduate Awards for Excellence.
Zachary Geiger, Sarah Elizabeth Logsdon, Andrew Jordan McLeod, Charles Neil and Sam Stanwyck

Last modified: 10/21/2010

UCSD's POLARBEAR experiment is moving to its permanent location in the Atacama Desert, Chile

news picture

Following a successful "first-light" four-month observing run, UCSD's POLARBEAR experiment on the Huan Tran Telescope at the James Ax Observatory located in the Inyo National Forest near Bishop, CA, is moving to its permanent location in the Atacama Desert, Chile.

POLARBEAR is a collaboration between UC San Diego,
UC Berkeley, University of Colorado, McGill University, Imperial College, the Japanese High Energy Research Organization, and the University of Paris.
Polarbear's goal is to detect the gravitational waves produced during the era of inflation, shortly after the Big Bang by observing unique patterns of polarization of the Cosmic Microwave Background (CMB) radiation. These gravitational waves would be a telltale sign that inflation indeed took place. Additionally, measurement of the small angular scale polarization patterns have the capability to constrain the properties of Dark Matter and the mass of the neutrinos.

POLARBEAR's receiver is able to detect the polarization of the CMB radiation through an array of over 1200 superconducting transition edge sensor bolometers cooled to 0.25 degrees Kelvin to reduce noise. Many months of observations must be combined to improve the signal to noise enough to observe the desired signals. Atmospheric water vapor is the enemy of ground-based
microwave background measurements, hence the move to one of the driest sites on earth: the Atacama Desert, Chile where at an altitude of 16,500 feet, water vapor is greatly reduced.

The POLARBEAR team has begun decommissioning the temporary observatory in the Inyo mountains which will be reassembled in Atacama for observations starting in early 2011.

Polarbear team members from UC San Diego are David Boettger, George Fuller, Brian Keating, Nathan Miller, Hans Paar, and Ian Schanning.

Last modified: 09/09/2010

David Kleinfeld receives $2.5 million NIH Director's Pioneer Award

news picture Physics professor David Kleinfeld will receive a $2.5 million Director's Pioneer Award from the National Institutes of Health for his work on the control of blood flow in the brain. Kleinfeld and his colleagues will use emerging genetic and optical tools to determine how chemical signals from brain cells control the distribution of blood, a vital and limited resource in the brain. The work bears on all aspects of brain function, Kleinfeld said, including the resilience of cognitive processes to damage caused by vascular trauma or disease. The grants are designed to support individual scientists of exceptional creativity who propose pioneering – and possibly transforming approaches – to major challenges in biomedical and behavioral research and contributions to science.

Last modified: 08/10/2010

2010 Ma and Malmberg Award Recipients: Arielle Lynn Yablonovitch and Adrian Felix Caudillo

news picture This year's Physics Department's recipients of the Shang-keng Ma Memorial Award Endowed by the Shaoyeh Ma Foundation and Malmberg awards are Arielle L. Yablonovitch and Adrian F. Caudillo. The selection committee, consisting of Professors Fred Driscoll, Hans Paar, and Clifford Surko, after considerable debate and assessing the students academic achievements selected Arielle to receive the John Holmes Malmberg award and Adrian to receive the Shang Keng Ma award.

Last modified: 08/04/2010

UCSD Physicist Dr. Vitali Shapiro Dies at 73

news picture Vitali Shapiro, a plasma physicist who made numerous important contributions into the theoretical studies of laboratory, geophysical and astrophysical plasmas, died June 28 at the age of 73 at his home in San Diego. He was a professor emeritus at the Physics Department, University of California, San Diego.
Shapiro's scientific career began in late 50-s at the Physical-Technical Institute in Kharkov, Ukraine. During his Kharkov years, he authored and co-authored many scientific research papers which became classics in the physics of beam-plasma interactions and quasi-linear theory of plasma instabilities, in particular the anisotropic velocity distribution instability. He earned his Ph.D. from the Joint Institute for Nuclear Research in the former Soviet Union in 1963, and a subsequent D.Sc. from the USSR's Institute for Nuclear Physics in Novosibirsk in 1967.
In 1976, Shapiro moved to the Space Research Institute of the Soviet Academy of Sciences in Moscow, where he was elected head of the Laboratory for Fundamental Plasma Studies. His scientific interests expanded towards studies of strong Langmuir turbulence including the wave collapse phenomena, the physics of magnetosphere and solar wind, collisionless shocks, cometary plasmas and astrophysical phenomena. He will also be remembered as a great teacher being a Professor of Space Physics at the Moscow Physical-Technical Institute.
Shapiro joined the UCSD faculty in 1994, with joint appointments in the Jacobs School and the Department of Physics. In 1992-94, he was a Research Physicist at the University of California's system-wide California Space Institute. Among his many honors and awards is the USSR State Prize in Physics for his contributions to the theory of nonlinear dynamics of the completely ionized plasma (1987). He was a Fellow of the American Physical Society, and served as an Associate Editor of the Journal of Geophysical Research.
A private funeral service was held on June 30. Condolences may be sent to the family at: 3760 Millikin Avenue, San Diego, CA 92122.

Last modified: 07/06/2010

Peter Wolynes Departs for Lecture-Tour of China on an Einstein Professorship from Chinese Academy of Sciences

news picture Peter Wolynes, professor of chemistry and biochemistry and of physics and senior scientist with the Center for Theoretical Biological Physics, has been awarded a 2010 Einstein Professorship by the Chinese Academy of Sciences.
As an Einstein Professor, Wolynes will visit academy institutes in several Chinese cities in July as part of a program to strengthen cooperation and exchange between leading scientists in China and other countries. His visit will culminate in two lectures at the Changchun Institute of Applied Chemistry in Changchun, Jilin, spanning the breadth of his current research interests. Wolynes will talk about his recent advances in protein folding studies in one presentation and discuss the glass transition in the other.
The academy awards 20 Einstein Professorships each year to distinguished international scientists working at the frontier of any scientific discipline.

Last modified: 07/02/2010

Professor Oleg Shpyrko receives an NSF CAREER Award

news picture

UCSD physics Professor Oleg Shpyrko has received an NSF Faculty Early Career Development Program (CAREER) Grant. The CAREER Program offers the National Science Foundation's most prestigious awards in support of junior faculty who exemplify the role of teacher-scholars through outstanding research, excellent education and the integration of education and research within the context of the mission of their organizations. This Faculty Early Career Award will support research aiming to investigate the relationship between dynamical, mechanical, and structural properties of nanoscale-thick films, using synchrotron x-ray surface scattering probes at both the existing and the next generation light sources. Understanding the fundamental relationship between structure and function of materials such as biological membranes, self-assembled monolayers and thin polymer films at the nanoscale is crucial for many disciplines ranging from condensed matter and chemistry to biology, engineering and nanotechnology. More information on Prof. Shpyrko's research is available at http://oleg.ucsd.edu.

Last modified: 05/31/2010

UC San Diego Physicists Locate Long Lost Soviet Reflector on Moon

news picture A team of physicists led by a professor at UC San Diego has pinpointed the location of a long lost light reflector left on the lunar surface by the Soviet Union nearly 40 years ago that many scientists had unsuccessfully searched for and never expected would be found.

The French-built laser reflector was sent aboard the unmanned Luna 17 mission, which landed on the moon November 17, 1970, releasing a robotic rover that roamed the lunar surface and carried the missing laser reflector. The Soviet lander and its rover, called Lunokhod 1, were last heard from on September 14, 1971.

"No one had seen the reflector since 1971," said Tom Murphy, an associate professor of physics at UCSD. He heads a team of scientists engaged in a long-term effort to look for deviations of Einstein's theory of general relativity by measuring the shape of the lunar orbit to within an accuracy of one millimeter, or about the thickness of a paperclip. This is accomplished by timing the reflections of pulses of laser light from reflectors left on the moon by Apollo astronauts and turning the timing measurement into a distance.

"We routinely use the three hardy reflectors placed on the moon by the Apollo 11, 14 and 15 missions," said Murphy, "and occasionally the Soviet-landed Lunokhod 2 reflector--though it does not work well enough to use when illuminated by sunlight. But we yearned to find Lunokhod 1."

Three reflectors are required to lock down the orientation of the moon. A fourth adds information about tidal distortion of the moon, and a fifth enhances that information.

"Lunokhod 1, by virtue of its location, would provide the best leverage for understanding the liquid lunar core, and for producing an accurate estimate of the position of the center of the moon--which is of paramount importance in mapping out the orbit and putting Einstein's gravity to a test," said Murphy.

Murphy said his team had occasionally looked for the Lunokhod 1 reflector over the last two years, but faced tall odds against finding it until recently. The breakthrough came last month when the high-resolution camera on NASA's Lunar Reconnaissance Orbiter, or LRO, obtained images of the landing site. The camera team, led by Mark Robinson at Arizona State University, identified the rover as a sunlit speck on the image--miles from where Murphy and his team had been searching. (see:http://www.nasa.gov/mission_pages/LRO/multimedia/lroimages/lroc-20100318.html ) But until now the existence of the reflector or its precise location was unknown.

"It turns out we were searching around a position miles from the rover," said Murphy. "We could only search one football-field-sized region at a time. The recent images from LRO, together with laser altimetry of the surface, provided coordinates within 100 meters, and then we were in business and only had to wait for time on the telescope in good observing conditions."

On April 22, his team sent pulses of laser light from the 3.5 meter telescope at the Apache Point Observatory in New Mexico, zeroing in on the target coordinates provided by the LRO images. Murphy, together with Russet McMillan of the Apache Point Observatory in Sunspot, NM, and UCSD physics graduate student Eric Michelsen found the long lost Lunokhod 1 reflector and pinpointed its distance from earth to within one centimeter. They then made a second observation less than 30 minutes later that allowed the team to triangulate the reflector's latitude and longitude on the moon, in other words its exact spot on the moon, to within 10 meters--"not bad for a half-hour's work," said Murphy. In the coming months, he estimates it will be possible to establish the reflector's coordinates to better than one-centimeter precision.

The return signal from the reflector was measured by Murphy's team as a collection of individual particles, or photons, of laser light.

"We quickly verified the signal to be real and found it to be surprisingly bright: at least five times brighter than the other Soviet reflector, on the Lunokhod 2 rover, to which we routinely send laser pulses," Murphy said. "The best signal we've seen from Lunokhod 2 in several years of effort is 750 return photons, but we got about 2,000 photons from Lunokhod 1 on our first try. It's got a lot to say after almost 40 years of silence."

The discovery of the Soviet reflector came as a surprise, because scientists had actively searched for it for nearly four decades without success. Many scientists had speculated that the Lunokhod 1 rover might have fallen into a crater or parked badly, with its reflector not facing the earth, which would have prevented it from being located by laser pulses.

"Not only now do we know that Lunokhod 1 is there, we also know that it is parked perfectly so that its reflector faces earth," said Murphy. "In fact, the signal is so surprisingly strong that the rover could not be in anything but a level parking spot with its last commanded roll on the lunar surface deliberately oriented toward the earth."

Murphy and his colleagues found in a study they published this month that lunar dust may be obscuring the reflectors on the moon. see: Moon Dust His team found that the laser light they bounce off reflectors on the moon is fainter than expected and dims even more whenever the moon is full.

"Near full moon, the strength of the returning light decreases by a factor of ten," he adds. "We need to understand what is causing this if we are contemplating putting additional scientific equipment on the moon. Finding the Lunokhod 1 reflector will add important clues to this study."

Murphy's project, dubbed APOLLO (the Apache Point Observatory Lunar Laser-ranging Operation), is supported by the National Science Foundation and NASA, and includes scientists at the University of Washington, Harvard University, the Massachusetts Institute of Technology, Humboldt State University and the Apache Point Observatory.

Last modified: 04/28/2010

Can the Newest Form of Carbon Be Made to Bend, Twist and Roll?

news picture Can graphene--a newly discovered form of pure carbon that may one day replace the silicon in computers, televisions, mobile phones and other common electronic devices--be made to bend, twist and roll?
Physicists at UC San Diego and Boston University think so. In a paper published in the journal Physical Review B, the scientists say the propensity of graphene--a single layer of carbon atoms arranged in a honeycomb lattice-- to stick to itself and form carbon "nanoscrolls" could be controlled electrostatically to form a myriad of new devices.
Unlike carbon nanotubes--cylindrical molecules of pure carbon with novel properties that have become the focus of much of the attention of new application in electronics and materials development--carbon nanoscrolls retain open edges and have no caps. "As a result, nanoscrolls can change their shape and their inner and outer diameters, while nanotubes cannot," said Michael Fogler, an associate professor of physics at UCSD and the first author of the paper.
Working with Antonio Castro Neto, a physics professor at Boston University, and Francisco Guinea of the Institute of Materials Science in Madrid, the scientists proposed the construction of a device in which the electronic properties of graphene are used to roll and unroll the nanoscroll.
"The device we envision is a graphene nanoscroll that can be charged by current from a nearby electrode," said Fogler. "The more charged it becomes, the more the mutual electrostatic repulsion of electrons inside the scroll causes it to unwrap. So, the voltage on the electrode can control the diameter and the number of coils in the scroll."
"We show in this paper that the electrostatic control of nanoscrolls is very much feasible. The required voltages are in the practical range. Since graphene is so light, the wrapping and unwrapping would occur on a time scale of one-trillionth of a second. So, not only the degree of scrolling can be controlled, these nano-electromechanical devices will also be ultra-fast."
Fogler said such nanoscrolls could have a wide range of applications, such as actuators whose operation resembles the blinking of one's eyes, valves in lab-on-a-chip devices and even a form of electronic paper. Previously, other scientists attempted to build scroll "machines" using thin plastic films but they were either too rigid or too frail to work well. In contrast, nanoscrolls made of graphene, which is mechanically stronger than any other material known to man, would be robust, yet remain ultra-light and ultra-flexible. They would also conduct electricity more than a thousand times better than silicon.
Fogler said that the ideas to use electrical properties of graphene to modify its structure, or vice versa, are still quite new, and so the proposed devices may require some time to develop. In the near term, scientists hope that graphene, which is an optically transparent conductor of electricity, could be used to replace current liquid crystal displays that employ thin metal-oxide films based on indium, a rare metal that is becoming increasingly expensive and likely to be in short supply within a decade.
An advance copy of the journal article appeared online this week at:
The study was funded by grants from the National Science Foundation and U.S. Department of Energy.

Full Story

Last modified: 04/13/2010

Physicists Begin Quest for 'Higgs' Particle at European Collider

news picture More than two dozen UC San Diego physicists and technicians began their long-awaited quest last week in a research facility below the Swiss-French border to find a hypothetical subatomic particle that they hope will allow them to finally tie together the fundamental forces and particles in nature into one grand theory.
With cheers, applause and toasts of champagne, hundreds of physicists at CERN, the European Organization for Nuclear Research near Geneva, successfully collided beams of protons, moving in opposite directions at close to the speed of light, with an energy greater than has ever been produced before on Earth.
From the millions of subatomic particle collisions in this newly constructed collider, known as the Large Hadron Collider, or LHC, the scientists hope to generate tiny fireballs of pure energy, from which new particles never before seen on Earth emerge. That should provide them with clues to improve on and go beyond their basic theory of nature--what they call the Standard Model.
"It's taken us 25 years to build," Vivek Sharma, a physics professor at UCSD now working at CERN, said of the LHC in a news conference last week that was reported in newspapers, magazines and broadcasts worldwide. "This is what it's for. Finally the baby is delivered. Now it has to grow."
The LHC is the world's largest scientific experiment, involving an estimated 10,000 individuals from 60 countries, including more than 1,700 scientists and engineers from 95 U.S. universities and laboratories. It will attempt to reproduce, on a miniature scale, some of the same conditions that occurred during the first fractions of a second after the Big Bang, when our universe is thought to have come into being some 14 billion years ago.
The main object or particle of the LHC's search is the Higgs boson, hypothesized by physicists to have been created in the Big Bang's fireball and to imbue particles with mass. It has never been detected by any of the world's previously built colliders. And it is thought to exist at energy levels that only the LHC can reach.
"Finding the Higgs Boson will be a marathon challenge, not an easy sprint," said Sharma, who will be living at CERN during the next few years to direct and coordinate the Higgs boson search for several hundred physicists at more than 38 countries and 183 institutes worldwide. "But we have set the traps with considerable thought and are confident that we will find it in not too distant future. The thrill of the chase is overwhelming and it will energize us through the course leading to its discovery."
Sharma and 27 other UCSD physicists and technicians have been shuttling between La Jolla and CERN during their sabbaticals and teaching breaks, for more than a decade now, to make sure that when the LHC is properly operating, data can be collected from one of the European collider's two big particle detectors--the Compact Muon Solenoid, or CMS. "The CMS detector is 21 meters long, 16 meters in diameter and weighs around the same as 30 jumbo jets or 2,500 African elephants," said Sharma "And though it is the size of a small cathedral, it contains detectors more precise than Swiss watches."
Because of the huge volume of data expected from this experiment, the UCSD team has designed and built the largest data acquisition system in the world to analyze the more than 100,000 collisions per second that will be generated when beams of protons circulating at nearly the speed of light in opposite directions around the 27-kilometer LHC ring are brought together in violent collisions.
"When the two proton beams collide, they will generate, within a tiny volume, temperatures a billion times hotter than in the heart of our Sun," said Sharma.
Sharma said the detector itself is capable of operating like a 100 megapixel digital camera taking 40 million photos a second. And the 15 million gigabytes of data expected to be generated each year by the CMS experiment will produce the equivalent of 20 million CDs of data that will require the computing power of about 100,000 of the fastest PC computers. While all of this hardware had been checked and rechecked, the situation was still tense last week, Sharma said, when the LHC's first three attempts at colliding beams failed in the early morning hours because of niggling hardware issues in the big collider. But these were quickly fixed, and when the collider started to collide protons at a rapid fire rate, some 60 times a second, Sharma said he and the other UCSD scientists felt a sense of relief and exhilaration for the discoveries that are sure to come in the near future.
"My heart stopped when the first event was splashed on the screen," he said. "The joy of watching CMS quickly and seamlessly take in all the LHC collisions and produce beautifully reconstructed events of proton-on-proton collisions is hard to communicate. LHC and CMS worked in tandem, like a dream machine."
Complete Article

Last modified: 04/07/2010

UC San Diego Physicist Robert Dynes Elected to National Academy of Sciences Governing Council

news picture Two scientists from UC San Diego have been elected to the governing council of the National Academy of Sciences, the nation's preeminent organization of scientists, which advises Congress and the U.S. government on matters of science and technology.
They are former UC San Diego Chancellor and University of California President Robert C. Dynes, now a professor of physics at UCSD, and Susan S. Taylor, a professor in UCSD's Department of Chemistry and Biochemistry and Department of Pharmacology, and a Howard Hughes Medical Institute Investigator.
The two UCSD scientists were among four members of the National Academy of Sciences elected this week to three-year terms on its governing council. Their terms begin on July 1.
Larry Squire, a professor of psychiatry at UC San Diego, currently serves on the academy's governing council, which means three of the 12 members of the governing council are now from UC San Diego, a remarkable achievement for any research institution.

Last modified: 03/08/2010

Professor Patrick Diamond named Director of New Fusion Theory Institute - Daejeon, Korea

news picture A group lead by Prof Patrick Diamond was recently awarded a 5 year, $2million per year grant to establish a Fusion Theory Institute at the National Fusion Research Institute (NFRI) in Daejeon, Korea. Diamond will become Director of the new Institute,which is located nearby the new, superconducting KSTAR tokamak, one of the two most advanced magnetic confinement experimental facilities in the world.

The new institute will focus on problems in plasma turbulence,transport and confinement optimization. While close collaboration with the KSTAR program is anticipated,the institute will be interdisciplinary and will also address problems in nonlinear dynamics and plasma astrophysics. Diamond will spend a significant amount of time in Daejeon,and plans to build strong collaborations between NFRI and UCSD, especially with the new DOE Center for Momentum Transport and Flow Organization (CMTFO) that Prof George Tynan (MAE) and he lead.

The new institute was awarded as an outcome of a competition involving all areas of science and technology under the auspices of Korea's WCI Program.

Last modified: 02/16/2010

Renowned UC San Diego Astrophysicist and Astronomer Geoffrey Burbidge Dies at 84

news picture Geoffrey Burbidge, a renowned British astrophysicist and astronomer at the University of California, San Diego who made contributions to our understanding of how elements are formed in stars as well as modern cosmology and radio galaxies, died on January 26 at the Scripps Memorial Hospital in La Jolla after a long illness. He was 84. Burbidge's towering stature in the field was reflected by his position as editor-in-chief of the Annual Review of Astronomy and Astrophysics for 30 years, his directorship of the Kitt Peak National Observatory in Tucson and his numerous prizes from astronomical societies around the world. In 2005, he and his wife Margaret, both of whom were founding members of UC San Diego's Department of Physics, were awarded the British Royal Astronomical Society Gold Medal, the society's highest honor, for their contributions to astronomy during more than half a century.

The two astronomers, who both worked actively until recent years at the university's Center for Astrophysics and Space Sciences, coming to campus each day and publishing papers, are best known for their work in the mid-1950s describing how stars synthesize nearly all the chemical elements in the universe, from carbon and iron to lead and uranium. That work was summarized in a seminal paper on stellar nucleosynthesis published in 1957 with two other legendary scientists- British astronomer Sir Fred Hoyle and American physicist William Fowler. Two years later, the two Burbidges received the American Astronomical Society's highest honor for young astronomers, the Warner Prize. "This was without question one of the most important papers of all time in astrophysics," said Mark Thiemens, dean of the Division of Physical Sciences at UCSD. "I've read it many times. Geoff was one of the most noteworthy astrophysicists of the past 50 years."

"This paper laid the foundation for an entirely new kind of synthesis of astronomical observations with frontier nuclear and particle science, paving the way for much of modern astrophysics and cosmology," said George Fuller, a nuclear astrophysicist and the director of the Center for Astrophysics and Space Sciences, or CASS. Burbidge pioneered the development of several sub-disciplines in astrophysics.

"He is famous for his work on radio galaxies in which he was the first to determine the enormous energies involved," said Art Wolfe, an astrophysicist at UCSD and former director of CASS. "This work ultimately led astrophysicists to consider gravitation as the energy source for these objects as well as for quasars. Much of the Burbidges' work revolved around the nature of quasars and active galactic nuclei. During the 1960s the Burbidges were virtually alone in their efforts to measure the masses of galaxies from their rotation speeds."

"Geoff Burbidge also was the first to show that the helium in the universe could not have come from stellar nucleosynthesis alone," said Fuller. According to close colleagues, all of his work had a profound influence on the development of modern astrophysics and cosmology. On the Big Bang theory, he was a contrarian. He, with Fred Hoyle and others, argued controversially for a quasi-steady state cosmology in which quasars are new matter ejected from energetic galaxies in a cyclic universe. In this view, bright quasars are nearby objects in spite of their high redshifts. He maintained this position right up to his last paper, published shortly before his death, in which he presented statistical evidence that bright quasars are strongly overabundant nearby active spiral galaxies.

Burbidge was born on September 24, 1925 in Chipping Norton, England and received his bachelor's degree from the University of Bristol and his doctorate in theoretical physics from University College in London. From 1950 until his arrival at UC San Diego in 1962, he held research and teaching positions at the University of London, Harvard, Cambridge, Chicago, Caltech and the Mt. Wilson and Palomar Observatories. He served as a professor of physics at UC San Diego from 1963 until 2002, except for the period from 1978 to 1984, during which he served as director of the Kitt Peak National Observatory.

In addition to the Warner Prize and the Royal Astronomical Society's Gold Medal, Burbidge received the Catherine Wolfe Bruce Gold Medal in 1999 from the Astronomical Society of the Pacific and was its president from 1974 to 1976. He also won the Jansky Prize of the National Radio Astronomy Observatory in 1985, the National Academy of Sciences Award for Scientific Reviewing in 2007 and served for many years as the scientific editor of The Astrophysical Journal. He was an elected fellow of the Royal Society, American Academy of Arts and Sciences, American Physical Society and University College, London.

Geoffrey Burbidge is survived by his wife, Margaret of La Jolla; his daughter Sarah of San Francisco; and his grandson, Connor Loeven. In lieu of flowers, the family wishes that donations be made to the San Diego Humane Society, 5500 Gaines Street, San Diego, CA 92110
There will be a memorial tribute for Geoffrey Burbidge at 11:00 am on Sunday April 18 at the Scripps Seaside Forum, which is just south of the Scripps Pier in La Jolla. The address is 8610 Kennel Way (formerly Discovery Way) La Jolla, CA 92037. Adjacent parking will be available. Doors will open at 10:15 a.m. A reception will follow on the lawn in front of the Forum, overlooking the sea.
For more information please call 858-534-6626.
Website for directions:

Last modified: 03/16/2010

Bacteria Provide New Insights into Human Decision Making

news picture Scientists studying how bacteria under stress collectively weigh and initiate different survival strategies say they have gained new insights into how humans make strategic decisions that affect their health, wealth and the fate of others in society.

Their study, published this week in the early online edition of the journal Proceedings of the National Academy of Sciences, was accomplished when the scientists applied the mathematical techniques used in physics to describe the complex interplay of genes and proteins that colonies of bacteria rely upon to initiate different survival strategies during times of environmental stress. Using the mathematical tools of theoretical physics and chemistry to describe complex biological systems is becoming more commonplace in the emerging field of theoretical biological physics.

The authors of the new study are theoretical physicists and chemists at the University of California, San Diego's Center for Theoretical Biological Physics, the nation's center for this activity funded by the National Science Foundation, and Tel Aviv University in Israel. They say that how genes are turned on and off in bacteria living under conditions of stress not only shed light on how complex biological systems interact, but provide insights for economists and political scientists applying mathematical models to describe complex human decision making. Continued...

Last modified: 01/05/2010

Discovery Brings New Type of Fast Computers Closer to Reality

news picture Physicists at UC San Diego have successfully created speedy integrated circuits with particles called "excitons" that operate at commercially cold temperatures, bringing the possibility of a new type of extremely fast computer based on excitons closer to reality.
Their discovery, detailed this week in the advance online issue of the journal Nature Photonics, follows the team's demonstration last summer of an integrated circuit"an assembly of transistors that is the building block for all electronic devices"capable of working at 1.5 degrees Kelvin above absolute zero. That temperature, equivalent to minus 457 degrees Fahrenheit, is not only less than the average temperature of deep space, but achievable only in special research laboratories.
Now the scientists report that they have succeeded in building an integrated circuit that operates at 125 degrees Kelvin, a temperature that while still a chilly minus 234 degrees Fahrenheit, can be easily attained commercially with liquid nitrogen, a substance that costs about as much per liter as gasoline.

"Our goal is to create efficient devices based on excitons that are operational at room temperature and can replace electronic devices where a high interconnection speed is important," said Leonid Butov, a professor of physics at UCSD, who headed the research team. "We're still in an early stage of development. Our team has only recently demonstrated the proof of principle for a transistor based on excitons and research is in progress."
Excitons are pairs of negatively charged electrons and positively charged "holes" that can be created by light in a semiconductor such as gallium arsenide. When the electron and hole recombine, the exciton decays and releases its energy as a flash of light.
The fact that excitons can be converted into light makes excitonic devices faster and more efficient than conventional electronic devices with optical interfaces, which use electrons for computation and must then convert them to light for use in communications devices.
"Our transistors process signals using excitons, which like electrons can be controlled with electrical voltages, but unlike electrons transform into photons at the output of the circuit," Butov said. " This direct coupling of excitons to photons allows us to link computation and communication."
Other members of the team involved in the discovery were physicists Gabriele Grosso, Joe Graves, Aaron Hammack and Alex High at UC San Diego, and materials scientists Micah Hanson and Arthur Gossard at UC Santa Barbara.
Their research was supported by the Army Research Office, the Department of Energy and the National Science Foundation.

Last modified: 10/05/2009

Physics and MAE Faculty Win DOE Plasma Science Center

news picture Pat Diamond and George Tynan (MAE) were awarded a Department of Energy Plasma Science Center in a recent competition held by the Office of Fusion Energy Sciences, Dept of Energy. Tynan (PI) and Diamond (lead Co-PI) will lead the new Center for Momentum Transport and Flow Organization, which will study momentum transport, flows, rotation and turbulence in tokamaks, basic laboratory experiments, and astrophysical objects such as the solar tachocline and accretion disks.
The interdisciplinary Center will involve researchers at UCSD, UCI, UCSC, Univ Wisconsin, Courant Institute (NYU), and the Princeton Plasma Physics Lab. The new center will work synergistically with Diamond's existing SciDAC Center for Turbulent Transport in Burning Plasmas. The total funding of the new CMTFO will be approximately $6.7 million over 5 years.

Last modified: 06/08/2009

Institute for Pure and Applied Physical Sciences (IPAPS) researchers win major Interdisciplinary awards from the Department of Defense

news picture Members of the Institute for Pure and Applied Physical Sciences are major contributors to 3 out of 22 Multidisciplinary University Research Initiatives (MURI's) awarded by the Department of Defense nation wide.
The MURI titled "Search for New Superconductors for Energy and Power Applications" funded at a level of $ 7M, directed by Prof. I. K. Schuller, will search for new superconductors for a variety of applications. The photograph shows the type of equipment that Prof. Schuller's team will be using for the discovery of new superconductors. Prof. M. B. Maple is one of the principal investigators in the MURI titled "Broad Based Search for New and Practical Superconductors."
Prof. L. J. Sham is a principal investigator in a MURI titled "Quantum Optical Circuits of Hybrid Quantum Memories." These MURI initiatives are all dedicated to interdisciplinary work in which researchers from many disciplines including physics, chemistry, materials science and engineering are jointly tackling important problems for the nation. The Physical Sciences Division at UCSD is a strong supporter of this type of interdisciplinary research which also provides the facilities and research funds to support young pre and post doctoral researchers.

Last modified: 05/22/2009

Physics Department 2009 Memorial Lecture - "Electrons and Holes in Carbon Nanotubes: Particle Physics Writ Small"

news picture The Physics Department Memorial Lecture series was organized in memory of Professor Norman M. Kroll, a pioneer in quantum physics and a founding member of the UCSD Physics Department. During his forty year career at UCSD, Professor Kroll made brilliant contributions to research in quantum electrodynamics, atomic physics, particle physics, free electron lasers and subatomic particle accelerators.
This lecture is generously supported by financial contributions from the Kroll family and friends, the Department of Physics, and the Institute of Physics & Applied Physical Sciences.
4:00 P.M.
Thursday, May 28, 2009
Basic Science Building, Garren Auditorium
3:30 P.M. Reception - Basic Science Building Courtyard
About the Speaker
Professor Paul L. McEuen is a leading expert in carbon nanotubes and applications of nanoelectronics in chemistry and biology. His research explores the science and technology of nanostructures, particularly carbon-based systems such as nanotubes and graphene, novel fabrication techniques at the nanometer scale, scanned probe microscopy of nanostructures, and the assembly and measurement of chemical and biological nanostructures.
Dr. McEuen is currently the Goldwin Smith Professor of Physics at Cornell University, which he joined in January 2001. From 1992 to 2000, he was a principal investigator at the Lawrence Berkeley National Laboratory, where he received the LBNL Outstanding Performance Award in 1997. In 2001, Dr. McEuen was awarded the Agilent Technologies Europhysics Prize for his pioneering research in carbon nanotubes.

Last modified: 05/06/2009

UCSD professor Brian Keating uses telescopes to study the precise moment the universe was created

news picture Several crates containing what will be one of the most powerful radio telescopes in the world are now en route from Bergamo, Italy to the Port of Long Beach. Its ultimate destination is the Atacama Desert in Chile, one of the driest places on earth, and one of the best for astronomical observations.
The telescope will be fully functional in about a year. And when that time comes University of California, San Diego cosmologist Brian Keating and his colleagues will have the inside track in the race to become the first to discover what happened in the first billionth of a billionth of a billionth of a second after the universe was formed.
If Keating's group, which includes UCSD's Hans Paar, and researchers from UC Berkeley, as well as some from Canada, France and Japan, was to achieve this insight into what he calls the "embryonic universe," they would not only be able to more precisely explain the origin of the universe, but also its future. Their reputations would be cemented in annals of astrophysics, and they'd be in the running for a Nobel Prize.
With the telescope, dubbed POLARBEAR (short for Polarization of Background Radiation), the scientists are trying to detect primordial gravitational waves. The existence of these waves would support the theory of inflation, which holds that right after the Big Bang, there was an incredibly rapid and violent expansion of the universe.
Full Article

Last modified: 05/06/2009

UC San Diego Assistant Professors Receive Hellman Faculty Fellows Awards

news picture Thirty-three assistant professors at the University of California, San Diego have been named recipients of the 2009-2010 Hellman Faculty Fellows Awards to support their research and creative activities.
The award program was established at UC San Diego through the generosity of Chris and Warren Hellman to provide financial support and encouragement to young faculty and enhance their progress toward tenure. "Due to the outstanding caliber of the proposals submitted, the selection process was quite a challenge this year," said Paul W. Drake, senior vice chancellor, Academic Affairs. "
Forty-two proposals were submitted by Arts & Humanities and Social Sciences faculty, of which 21 were selected for funding. Twelve proposals were selected for funding out of 24 submitted by the Biological Sciences, Physical Sciences and Engineering Divisions. Given the current economic climate, both selection committees chose to partially fund a number of these proposals in an effort to stretch the funds to assist a greater number of promising young faculty," Drake said.
Recipients of the Physical & Biological Sciences and Engineering awards include Ery Arias-Castro and Jiawang Nie, mathematics; Jennifer Cha and Liangfang Zhang, nanoengineering; Alison Coil, Olga Dudko and Oleg Shpyrko, physics; Joshua Figueroa and Michael Tauber, chemistry and biochemistry; Colin Jamora and Emily Troemel, cell and developmental biology; and Gert Lanckriet, electrical and computer engineering. Arts & Humanities and Social Sciences awardees were Syed Ali, economics; Ivano Caponigro, linguistics; Robert Castro, theatre and dance; Dennis Childs, Amelia Glaser, Anna Springer and Luis Martin-Cabrera, literature; Nitin Govil and John McMurria, communication; Adria Imada, Sara Kaplan and K. Wayne Yang, ethnic studies; Nancy Kwak and Patrick Patterson, history; Lei Liang, music; April Linton, sociology; Edmund Malesky, IR/PS; Sebastian Saiegh, political science; Clinton Tolley and Christian Wuthrich, philosophy, and Alison Wishard Guerra, education studies.

Last modified: 04/30/2009

Jose Onuchic named Fellow American Academy of Arts and Sciences

news picture Jose Nelson Onuchic, professor of physics and co-director of the Center for Theoretical Biological Physics was named Fellow of the American Academy of Arts and Sciences.
The American Academy of Arts & Sciences honors the country's leaders in scholarship, business, the arts and public affairs. New members will be formally welcomed into the Academy at an Induction Ceremony in Cambridge, Massachusetts, on October 10, 2009.
Founded in 1780, the Academy annually elects individuals who have made preeminent contributions to their disciplines and to society at large. The 2009 class of scholars, scientists, artists, civic, corporate and philanthropic leaders elected as fellows of the American Academy of Arts & Sciences includes 210 new Fellows and 19 new Foreign Honorary Members from 28 states and 11 countries.
Jose Nelson Onuchic has since 2002 co-directed the Center for Theoretical Biological Physics, which encompasses a broad spectrum of research and training activities at the forefront of the interface between biology and physics. This interdisciplinary approach--carried out jointly by physicists, chemists, mathematicians and biologists--has provided biologists with a better understanding of the underlying mechanisms governing complex biological systems. Onuchic's research centers on theoretical and computational methods for molecular biophysics and chemical reactions in condensed matter with a special focus on protein folding and electron transfer in biological systems. Onuchic received his bachelor's degrees in both physics and electrical engineering from the University of Sao Paulo in Brazil and his Ph.D. in chemistry from the California Institute of Technology. He is a Fellow of the American Physical Society and a member of the National Academy of Sciences.

Last modified: 04/27/2009

2009 Summer Graduate Teaching Fellows: Laura Tucker and Andrew Meyertholen

news picture Graduate students Laura Tucker and Andrew Meyertholen have been selected as 2009 Summer Graduate Teaching Fellows. This program provides the opportunity for advanced graduate students to participate in a mentored teaching experience as they prepare for and teach a summer session course. They were selected based on their outstanding performance as TAs and their interest in pedagogical issues. Prof. Michael Anderson will serve as their faculty mentor. Congratulations, Laura and Andrew!

Last modified: 02/23/2009

Graduate student Matt Krems and post-doctoral associate Yoni Dubi receive awards for excellence in research

news picture Graduate student Matt Krems (left) and post-doctoral associate Yoni Dubi (right) who work in the group of Prof. Di Ventra have won the "Kennedy Reed Award for Best Theoretical Research" (Matt) and the "Charles Kittel Award for Best Theoretical Research" (Yoni) of the American Physical Society at its California section meeting this past October. Matt has presented his recent work on fast DNA sequencing using transverse transport and in particular the effect of dephasing on the different properties of the four DNA bases. This work (funded by NIH) pertains to the quest for fast and cheap sequencing technologies with far-reaching consequences on society. Yoni won for his research (funded by DOE) on energy transport at the nanoscale and the conditions of validity of Fourier's law of heat conduction. This study is fundamental in advancing our understanding of how energy is carried in nanoscale systems and thus in our ability to build better devices for energy generation, storage and conversion."

Last modified: 12/09/2008

2008 Dean's Undergraduate Award for Excellence Physics Majors

news picture The Department of Physics is proud to announce the 2008 recipients in Physics: Aris Alexandradinata, Kathryn Chapin, Alex Freznel, Brennan Pursley and Thomas Tran. The Division of Physical Sciences established the Dean's Undergraduate Award for Excellence in 2004 to recognize undergraduate students who have demonstrated academic excellence and promise as researchers in the Division of Physical Sciences. Congratulations to this year's award recipients!

Last modified: 11/18/2008

First Detection of Magnetic Field in Distant Galaxy Produces a Surprise

news picture Using a powerful radio telescope to peer into the early universe, a team of California astronomers has obtained the first direct measurement of a nascent galaxy's magnetic field as it appeared 6.5 billion years ago.
Astronomers believe the magnetic fields within our own Milky Way and other nearby galaxies--which control the rate of star formation and the dynamics of interstellar gas--arose from a slow "dynamo effect." In this process, slowly rotating galaxies are thought to have generated magnetic fields that grew very gradually as they evolved over 5 billion to 10 billion years to their current levels.
But in the October 2 issue of Nature, the astronomers report that the magnetic field they measured in this distant "protogalaxy" is at least 10 times greater than the average value in the Milky Way.
"This was a complete surprise," said Arthur Wolfe, a professor of physics at UC San Diego's Center for Astrophysics and Space Sciences who headed the team. "The magnetic field we measured is at least an order of magnitude larger than the average value of the magnetic field detected in our own galaxy."
Complete Story

Last modified: 10/01/2008

UCSD Physicists Take Part in World's Largest Experiment

news picture
UC San Diego physics professor Frank Wuerthwein never thought his work as a particle physicist would be front page news. But when the world's largest particle collider turned on its beam of protons near Geneva on September 10, Wuerthwein began receiving text messages from people he hardly knew congratulating him on the accomplishment.
"I have never in my life seen my field attract so much attention," he said with amazement on his way to the airport for his 20-hour flight to Geneva.
Wuerthwein is one of 24 UCSD physicists involved in the Large Hadron Collider, or LHC, which this month begins the long-awaited quest to find the Higgs boson, a hypothetical particle that physicists hope will allow them to finally tie together the fundamental forces and particles in nature into one grand theory. It is the world's largest experiment, 15 years in the making and involving an estimated 10,000 individuals from 60 countries, including more than 1,700 scientists and engineers from 94 U.S. universities and laboratories.
Since 1994, UCSD physicists have been shuttling between La Jolla and Geneva during their sabbaticals and teaching breaks to work on one of the European collider's two big particle detectors--the Compact Muon Solenoid, or CMS. Make that a gigantic particle detector.
"The CMS detector is 15 meters in diameter and weighs around the same as 30 jumbo jets or 2,500 African elephants," said Vivek Sharma, a professor of physics who participated in the LHC's historic grand opening. "And though it is the size of a cathedral, it contains detectors as precise as Swiss watches."
Full Story

Last modified: 09/23/2008

(CTBP) Theoretical Biological Physics Center at UC San Diego Awarded $11 Million by National Science Foundation

news picture The National Science Foundation has announced it will provide $11 million over the next five years to continue the operation at UC San Diego of the world's leading center in the emerging field of theoretical biological physics.
The award was made to a group of physicists, chemists and mathematicians in UCSD's Division of Physical Sciences, in collaboration with a theoretical neuroscience group at the nearby Salk Institute for Biological Sciences. Using theoretical machinery from quantum mechanics and statistical mechanics, researchers at the center are demonstrating how physics can help scientists understand the complexity of biological systems, from proteins and DNA to cells and genetic networks to organisms and diseases.
The Center for Theoretical Biological Physics is one of nine NSF Physics Frontier Centers designed to foster aggressive and forward-looking research with the potential to lead to fundamental advances in physics.
Continue Full Story...

Last modified: 09/17/2008

2008 Research Experience for Undergraduates (REU) students take the "Physics of Sailing Course" on San Diego Harbor

news picture This summer the Physics Department again hosted the Research Experience for Undergraduates (REU) program. Nearly 20 students spend two months in research laboratories under the guidance of faculty and staff. They were selected out of hundreds of applicants.
The students attended a weekly seminar in which they were exposed to all research areas in our Department. One such seminar was on the Physics of Sailing offered by Hans Paar. The seminar had a laboratory component that took place on the San Diego Bay and the Pacific Ocean. The photo shows some of the students in action.
The REU program is sponsored by the National Science Foundation with Dmitri Basov PI and Hans Paar co-PI. The support from faculty and staff was greatly appreciated by all concerned.

Last modified: 09/08/2008

2008 Ma and Malmberg Award Winners

news picture This year's Physics Department's recipients of the Shang-keng Ma Memorial Award Endowed by the Shaoyeh Ma Foundation and Malmberg awards are Alex Dooraghi, Agnieszka Cieplak, and Brice Dorman. The selection committee consisting of Professors Fred Driscoll, Hans Paar, and Paolo Padoan considered an unusually large number of deserving students and made the selection only after considerable debate.
The committee selected two students to share the Malmberg Award, Alex Dooraghi and Agnieszka Cieplak, while Brice Dorman is the recipient of the Ma Award. Each of the students will receive a certificate and cash award of $750.
All three students have very high grades in their studies and have worked very hard to achieve this honor. Brice and Alex have only A+ and A grades in the Physics major courses while Agnieszka has excelled in experimental astrophysics.

Last modified: 06/12/2008

Several UCSD Physics Faculty designated American Physical Society "Outstanding Referees"

news picture UCSD Physicists R. C. Dynes, Benjamin Grinstein, Jorge Hirsch, Herbert Levine, Ivan K. Schuller and L. J. Sham have been designated "Outstanding Referees" by The American Physical Society.
This is the first year of this very selective award, and only 534 out of our 42,000 active referees have been chosen. In subsequent years, they intend to add about 130 more each year to the list of "Outstanding Referees." The awardees chosen are truly exceptional in their contributions to the physics community by their hard work and careful attention to the peer review process. These faculty members are to be congratulated.
The complete list of 534 awardees and other information about the award can be found at http://publish.aps.org/OutstandingReferees. The APS wishes to thank these awardees, for their exceptional work as anonymous referees in service to the international physics community.

Last modified: 06/05/2008

Professor Frank Wuerthwein and his group contributed to one of the American Institute of Physics' "top 10" physics results for 2007

news picture Professor Frank Wuerthwein and his group contributed to one of the American Institute of Physics' "top 10" physics results for 2007.
They provided two of the four measurements mentioned in number 7 on the list:
- First observation of WZ production (published in Physical Review Letters
- First measurement of ZZ production at a hadron collider (submitted to Physical Review Letters). Given that the Tevatron involves about 1500 physicists across two competing experiments from many countries worldwide, it is remarkable that a group of 6 people from UCSD were responsible for 50% of the recognized results while the other two measurements were completed by small armies of people from both experiments.

The two postdocs and one graduate student who were the primary drivers of this work have all obtained prestigous appointments:

- Mark Neubauer joined the University of Illinois at Urbana-Champaign as an Assistant Professor last summer.
- Elliot Lipeles is joining the University of Pennsylvania as an Assistant Professor in July 2008; and
- Shih-Chien Hsu has accepted a Chamberlain Fellowship at UC Berkeley, starting May 2008.

Two other UCSD students (Matt Norman, a 5th year Physics graduate student, and Rami Vanguri, an undergraduate Physics major) also participated in the research described above.

Professor Wuerthwein's group is now pushing out a number of other measurements, including the world's most sensitive Higgs search (Physical Review Letters in preparation). The group operates such that Rami, their undergraduate student, has the opportunity to contribute meaningfully to three papers, one of which was the WZ observation. For the two papers still in preparation, Rami is the primary author. Similarly, Matt has another paper in preparation for which he is the primary author, and there is one more paper in preparation for which Matt and Elliot are the primary authors.

The listings can be found at: http://www.aip.org/pnu/2007/split/850-1.html

Last modified: 05/01/2008

Graduate education programs in UC San Diego's Division of Physical Sciences continued to receive top national rankings by U.S. News and World Report, according to the magazine's most recent survey released March 27, 2008.

news picture Graduate education programs in UC San Diego's Division of Physical Sciences continued to receive top national rankings by U.S. News and World Report, according to the magazine's most recent survey released March 27, 2008.
The survey ranked discrete mathematics and combinations at UCSD 4th in the nation, plasma physics 7th, biochemistry 9th, condensed matter physics 10th, geometry and topology 15th, physics 16th , chemistry 20th and mathematics 24th.
The rankings are based on expert opinion about program quality and statistical indicators that measure the quality of a school's faculty, research, and students. The data come from surveys of more than 1,200 programs and some 14,000 academics and professionals that were conducted in fall 2007.
Information on how the magazine ranked other programs at UC San Diego can be obtained at: http://ucsdnews.ucsd.edu/newsrel/general/03-08UCSDReceiveHighRanks.asp#

Last modified: 04/04/2008

Alex Frenzel, Ilya Valmianski and Aris Alexandradinata awarded 2009 Ma and Malmberg Awards

news picture This year's Physics Department's recipients of the Shang-keng Ma Memorial Award Endowed by the Shaoyeh Ma Foundation and Malmberg awards are Alex Frenzel, Ilya Valmianski and Aris Alexandradinata. The selection committee consisting of Professors Fred Driscoll, Hans Paar, and Cliff Surko selected the top three students on the recommendations of faculty and staff. The committee selected two students to share the Ma Award, Ilya Valmianski and Aris Alexandradinata, while Alex Frenzel is the recipient of the Malmberg Prize. Each of the students will receive a certificate and cash award of $750. All three students have exceptional academic records and have worked very hard to achieve this honor. The students will go on to graduate programs in Physics and show great promise for successful careers. From left: Professor Hans Paar, Alex Frenzel, Aris Alexandradinata, Ilya Valmianski

Last modified: 02/28/2008

Physics professor Hans Paar and assistant professor Brian Keating are building what they call a POLARBEAR telescope to measure gravitational waves generated at the beginning of the universe.

news picture La Jolla Village News, December 2007 - A POLARBEAR will soon reside in the Inyo Mountains, thanks to a couple of UCSD astrophysicists. Physics professor Hans Paar and assistant professor Brian Keating are building what they call a POLARBEAR telescope to measure gravitational waves generated at the beginning of the universe.

Complete Story

Last modified: 12/17/2007

UCSD Consortium Receives $5.5 Million to Study Cell Migration

news picture The National Institute of General Medical Sciences of the National Institutes of Health has awarded a five year, $5.5 million Program Project Grant to a UCSD consortium to study chemotaxis--the directed movement of cells up a chemical gradient--in the social amoeba Dictyostelium discoideum. Chemotaxis is a key component in a multitude of biological processes, including neuronal patterning, wound healing, embryogenesis and angiogenesis--the formation of blood vessels.
The overall aim of the project is to quantitatively study three distinct and sequential stages of chemotaxis using an approach that integrates novel experiments and mathematical modeling. These stages include the initial directional sensing process during which several key signaling components localize subcellularly, cell polarity which leads to clearly distinguishable fronts, backs and sides of a cell and motility which includes actual cell movement.
Experiments performed as part of the project will rely heavily on the use of microfluidic devices, which consist of tiny canals on a microchip. Microfluidic devices will provide precise control over the chemoattractant stimulus--the chemicals that attract cells. The goal of the research is to better understand chemotaxis of eukaryotic cells. Advances in this field will benefit diagnosis and treatment of medical problems involving cell migration.
The consortium consists of two theoretical physicists (Wouter-Jan Rappel, the PI of the grant, and Herbert Levine), two biologists (Richard A. Firtel and William F. Loomis) and Alex Groisman, a microfluidics expert in the physics department.
The grant also includes a subcontract to a microfluidics group at Cornell University (Carl Franck and Eberhard Bodenschatz).

Last modified: 11/14/2007

Five Physics Majors Awarded Dean's Undergraduate Award for Excellence

news picture The Department of Physics is proud to announce the 2007 recipients in Physics: Alex Dooraghi, Brice Dorman, Adrian Fontanilla, Shaun Gordon and Ilya Valmianski. The Division of Physical Sciences established the Dean's Undergraduate Award for Excellence in 2004 to recognize undergraduate students who have demonstrated academic excellence and promise as researchers in the Division of Physical Sciences. Congratulations to this year's award recipients!

Last modified: 11/08/2007

$1 Million in Private Support to UC San Diego Completes Funding for Construction of Innovative POLARBEAR Telescope

news picture Thanks to two visionary donors, $1 million in gifts to the University of California, San Diego, has initiated the construction of a telescope that may--for the first time--enable physicists to measure "gravitational waves" from the Big Bang, giving unique insight into the condition of the universe at its inception. The groundbreaking project places UC San Diego at the forefront of the emerging field of observational particle-astrophysics.
"The implications of the research derived from this telescope will be unique and far-reaching," said Hans Paar, a UC San Diego professor of physics working on the project. "Our findings will capture the birth of the universe, providing a deeper understanding of one of the most compelling questions in all of science: How did our universe begin?"
After learning about the historic initiative and an initial $400,000 contribution from the James B. Ax Family Foundation to support the project, an anonymous donor gave UC San Diego's Divison of Physical Sciences the remaining $600,000 to advance the new research endeavor. Together, the two donations provide the funding needed to begin construction of the telescope for the project, dubbed "POLARBEAR" for Polarization of Background Radiation. Scientists from UC San Diego, UC Berkeley, Lawrence Berkeley National Laboratory and the University of Colorado are collaborating on the project, along with several researchers from universities in Canada, Britain and France. The telescope will initially be located at a University of California research facility in the Inyo Mountains, east of the Sierra Nevada Mountain Range near Bishop, California.
The telescope will allow scientists to probe a previously unexplored epoch of the universe, according to Brian Keating, an assistant professor of physics at UCSD and leading collaborator on the project. "The POLARBEAR project is a daring one," added Paar. "We are pushing the limits of what is possible and that is how progress is made."
For more information, please visit the POLARBEAR Telescope website: http://physics.ucsd.edu/~bkeating/polarbear.htm.
Media Contact: Jade Berggren, 858-822-5309

Last modified: 10/30/2007

Last modified: 08/31/2007

Peter Wolynes: Calculations Show How to Precisely Steer Molecules with Light

news picture Physical chemists from the University of California, San Diego and the University of Illinois, Urbana have determined the minimum amount of light energy required to control chemical reactions and move molecules.
The study, published August 6 in the on-line edition of the journal Physical Review Letters, extended Ulam's conjecture to the level of quantum objects. Ulam's conjecture, proposed in 1956 by American mathematician Stanislaw Ulam, is routinely used to guide spacecraft through the solar system by exploiting gravity. The researchers say that their calculations will make it possible to more precisely steer molecules using photons-or particles-of light.
"Ulam's conjecture was devised for objects large enough to be governed by Newtonian dynamics," explained Peter Wolynes, a professor in UCSD's department of chemistry and biochemistry and department of physics. "But, by contrast, the behavior of electrons in atoms and molecules is explained by quantum mechanics. Therefore, in our computations we used a wave function, which describes a quantum state, to determine the least amount of light energy needed to nudge molecules from one state to another."
A minimal series of energy expenditures can be used to transfer an object from one point to another more quickly than by spontaneous motion, according to Ulam's conjecture, because of certain characteristics of chaotic motion. To move spacecraft, that energy can come from the gravitational pull of celestial bodies.
"The idea is that a complex system like our solar system has lots of planets, moons, and asteroids that can fling spacecraft gravitationally anywhere you want," said Martin Gruebele, who is a professor of chemistry and physics and biophysics, and the director of the center for biophysics and computational biology at Illinois. "Rather than powering a rocket on a brute force, direct route, you can shoot your spacecraft near some moon, and let the moon do most of the work."
Researchers already use light to guide molecules, just as gravity is used to steer spacecraft in the solar system. For example, they use laser tweezers to trap and probe particles, including individual atoms. However, there was previously no way, other than trial and error, to know how much light energy was needed to move a molecule from one state to the next, or to determine how the amount of light energy needed changed as the complexity of the molecules changed.
Wolynes and Gruebele described all the possible states of a quantum mechanical system, and identified which states are closest to one another. They also determined the limits on how efficiently and quickly photons can push a quantum mechanical system from an initial state to a target state. They say that the quantum mechanical analog of Ulam's conjecture that they have created will expand the controllability and flexibility of quantum mechanical objects.
"We can wait for the best possible moment to use the least amount of energy," Gruebele said. "What we have is a fast and accurate method for computing the most efficient way of steering a quantum system between two specified states."
The study was funded by the National Science Foundation.
Additional information at: University of Illinois at Urbana-Champaign, College of Engineering

Last modified: 08/26/2007

Research Experience for Undergraduates (REU) students take the "Physics of Sailing Course" on San Diego Harbor

news picture Again this year Research Experience for Undergraduates (REU) students took the "Physics of Sailing" course given by Prof. Hans Paar. The course consisted of a lecture and a laboratory component, the latter in a Catalina 42 sailboat on the San Diego Bay and the Pacific Ocean. The photo shows the ten participating REU students, they all passed the course with flying colors.
The Physics Department's REU program is funded with a Grant by the NSF with Dmitri Basov and Hans Paar as co-PIs and Patti Hey as chief administrator (thanks Patti). The students are embedded in research groups within the Physics Department where they learn first-hand about research in an academic setting.

Last modified: 08/20/2007

Peter Wolynes Elected to the German Academy of Sciences Leopoldina

news picture Elected to the German Academy of Sciences Leopoldina in recognition of his scientific achievements and "personal standing."

Founded in 1652, the Leopoldina is the "world's oldest academy involved in the natural sciences that has been permanently in existence." The number of members is limited to 1,000 total in 28 subject sections. Wolynes will belong to the subsection of Theoretical Physics.

Wolynes has developed the leading theory of how proteins fold, which has led to computer algorithms that allow one to predict the three-dimensional structure of a protein from its amino acid sequence. His work on the theory of energy landscapes has also impacted condensed matter physics, notably illuminating the nature of glasses and liquids.

Last modified: 05/15/2007

Randy Kelley Wins 2007 LHC Theory Initiative Graduate Fellowship Award

news picture The Large Hadron Collider (LHC) Theory Initiative, a U.S.-based consortium of theoretical physicists aiming to stimulate and cultivate new young talent in anticipation of the opening of the Large Hadron Collider, awarded the 2007 LHC Theory Graduate Fellowship to Randy Kelley.
Randy Kelley is a third year graduate student in the physics department at UCSD. His current research, with his thesis advisor Professor Aneesh Manohar, is on the production of W and Z Bosons at the LHC using soft collinear effective theories.
Randy Kelley is well known in the UCSD community for his brilliant teaching of the undergraduates. He obtained his B.S. in physics from the University of Virginia and before joining UCSD, he was a Lieutenant in the US Navy where he served as a nuclear engineering officer onboard the USS John C Stennis.
Funded by the National Science Foundation, the $40,000 fellowship award provides young theorists selected in a national competition with funds to underwrite the costs of their research, including travel and computing needs.
"The goal of these fellowships is to stimulate the work of theoretical physicists who will help interpret the treasure trove of data that will emerge from the Large Hadron Collider" said Jonathan Bagger, a leader of the LHC Theory Initiative. "Our initiative will help the high-energy physics community take full advantage of the LHC."
The Large Hadron Collider at CERN, the European laboratory for particle physics in Geneva, Switzerland, is expected to begin operation late this year. With its unprecedented energy and luminosity, the LHC promises to revolutionize particle physics and our understanding of the universe. It is expected to create new forms of matter as scientists search for the elusive Higgs boson and a host of new particles, as well as help answer some of the most fundamental questions of physics. For more information on the LHC Theory Initiative visit http://www.lhc-ti.org

Last modified: 04/25/2007

Physics Department 2007 Memorial Lecture

news picture Prof. Malvin A. Ruderman, the Centennial Professor of Physics and of Applied Physics at Columbia University, will speak on Pulsars: Expected Evolution, Observations, and Speculations. This public event will be held at 4:00 pm on Thursday, May 3 in Garren Auditorium, located in the Basic Science Building on the UC San Diego campus.

Prof. Ruderman is a distinguished theoretical astrophysicist who pioneered the science of neutron stars and pulsars; he has also contributed to elementary particle physics and to understanding of the earth's atmosphere. He has worked intensively on problems associated with collapsed objects in astrophysics, especially neutron stars. Recent work has focused on how neutron stars convert so much of their initial spin-energy into beams of high energy radiation. Prof. Ruderman received his PhD. from Cal Tech in 1951. He was elected to the National Academy of Sciences in 1972 and to the American Academy of Arts & Sciences in 1974.

Talk Abstract: Forty years after the discovery of the first pulsars important questions still remain about the structure and dynamics of these strongly magnetized, rapidly spinning neutron stars. Expected properties and observable phenomena will be presented for a "standard model" of them. It assumes a near solar mass core of superfluid neutrons, superconducting protons and very relativistic degenerate electrons, all enclosed by a thin solid metal crust. The model describes a distinctive evolution of neutron star magnetic fields during prolonged stellar spin-down (or spin-up) and, associated with it, two families of sudden jumps in the star's spin-down torque and spin-rate. Model expectations are consistent with observations. However, understanding other kinds of observations, commonly interpreted as evidence for very long period neutron star precession, and also presumed thermal x-ray emission from the stellar surface, raise problems for this standard model. Other interpretations of these observations will be suggested.

The Physics Department Memorial Lecture series was organized in memory of Prof. Norman M. Kroll, a pioneer in quantum physics and a founding member of the UCSD Physics department. During his forty year career at UCSD, Prof. Kroll made brilliant contributions to research in quantum electrodynamics, atomic physics, particle physics, free electron lasers and subatomic particle accelerators.

This lecture is generously supported by financial contributions from the Kroll family and friends, the Department of Physics, and the Institute of Physics & Applied Physical Sciences. The event is free and open to the public.

Link to faculty website at Physics department, Columbia Universtiy

Last modified: 04/10/2007

M. Brian Maple Named Honorary Professor of the W. Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Wroclaw, Poland

news picture Professor M. Brian Maple was awarded the title of Honorary Professor of the W. Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Wroclaw, Poland. The Honorary Professorship was conferred at the Institute during the International Conference on f-Elements that was held in Wroclaw, September 20 - 25, 2006. Professor Maple is the 10th person, and first American, to be awarded an Honorary Professorship of the Institute since this honor was first bestowed in 1994. The conferment of the Honorary Professorship was conducted in Latin and included the presentation of a certificate and a medal. Following the Conferment Ceremony, Professor Maple gave a lecture entitled "Novel types of superconductivity in f-electron materials."

The Institute of Low Temperature and Structure Research was established in 1966 and is named after Professor W. Trzebiatowski, who played a key role in the establishment of the Institute, served as its first Director, and later became the President of the Polish Academy of Sciences. Professor Trzebiatowski is known for the discovery in 1952 of ferromagnetism in uranium hydride UH3. This came as a great surprise since metallic uranium was known to be completely nonmagnetic and, at that time, ferromagnetic ordering had only been found in metals and alloys of the iron group, as well as in gadolinium, one of the rare earth metals.

Professor Maple has collaborated with researchers at the W. Trzebiatowski Institute since 1976 and coauthored eight joint papers. His most recent projects with the Institute concern the nonmagnetic Kondo effect in actinides and the physics of strongly correlated electron behavior in lanthanide and actinide filled skutterudite arsenide compounds.

See full article here: http://physicalsciences.ucsd.edu/news_events/news_archives/2007_Archive/07.26.02.maple.poland.htm

Last modified: 02/28/2007

UC San Diego Professor Wins Wolf Prize in Chemistry

news picture UCSD Physicist George Feher, who uncovered the basic mechanisms for how plants and bacteria use photosynthesis to convert light into chemical energy, has been awarded the prestigious 2007 Wolf Prize in Chemistry. Israel's Wolf Foundation, which promotes "science and art for the benefit of mankind," announced the award today.

George Feher, a research professor at UCSD, will share the $100,000 prize with Ada Yonath of Israel's Weizmann Institute of Science" for ingenious structural discoveries of the ribosomal machinery of peptide-bond formation and the light-driven primary processes in photosynthesis." The award will be presented to the two scientists by the President of Israel at a formal ceremony at the Knesset, or parliament, in Jerusalem, on May 13.

Full Story

Last modified: 01/11/2007

UCSD Physicist Sally Ride one of 13 inducted into inaugural California Hall of Fame

news picture "On Dec. 6, 2006, Sally K. Ride, America's first female astronaut and UCSD physics professor, was recognized for her NASA accomplishments and efforts to encourage girls to nurture their childhood love of math and science. She is one of 13 inductees for the inaugural California Hall of Fame ceremony at the California Museum for History, Women & the Arts in Sacramento. For the full story, click on the following link." http://www.signonsandiego.com/news/metro/20061206-9999-7m6ride.html

Last modified: 12/12/2006

WZ couple: Discovering a match made in heavies

news picture Members of the UCSD Experimental Particle Physics Group, including graduate and undergraduate students (Mark Neubauer, Shih-Chieh Hsu, Elliot Lipeles, Frank Wurthwein and Rami Vanguri) made the first observation of WZ production warranting a "Result of the Week" at Fermilab National Laboratory.


From the Article:

"The mediators of the weak interaction, the massive W and Z gauge bosons, are readily produced at the Tevatron and have been studied extensively by the CDF and DZero experiments. But producing pairs of heavy gauge bosons is far more rare. While one W boson is produced in every 3 million Tevatron collisions, and one Z boson in every 10 million, WZ pairs are produced only once per 20 billion events. Facing these odds, it is no wonder that WZ has never been observed--that is, until now. The elusive WZ has finally been netted at CDF. We found it by searching for WZ production in its most easily observable signature, where 3 charged leptons are produced along with missing energy from a neutrino. CDF observed 16 of these signatures, and about 13 of them are expected to be WZ events. If WZ production was not actually happening in the Tevatron, the probability of getting this result would only be 2 in a billion. This indicates that our results are significant; and we have, in fact, observed WZ production. Finding the WZ pair is important because it teaches us about how gauge bosons interact with each other, and it confirms Standard Model predictions. Observing such a rare process at CDF also represents an important experimental milestone in our pursuit of the Higgs particle and new physics at the Tevatron. We look forward to a bright future as we continue to collect data from Run II!"

Last modified: 12/12/2006

Four undergraduate physics majors win Dean's Excellence Awards

news picture Four undergraduate physics majors have won Dean's Excellence Awards this year. They are Xinyi Lin, Andre Gomez, Rikiya Yoshida, and Morgan Brown. Each awardee will receive a cheque for $1000 at a ceremony this Friday, Oct. 27, 1:30-3PM, on the NSB Front Plaza.

Last modified: 10/29/2006

2006 UCSD Physics Ma and Malmberg Award Winners

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The Department of Physics is pleased to announce the winners of this year's Shang-keng Ma Memorial Award Endowed by the Shaoyeh Ma Foundation and Malmberg awards, our department's awards to the top undergraduate physics majors.
This years Ma award goes to Ethan Brown and the Malmberg award goes to Matthew Bibee. In addition to stellar GPAs, Ethan had 5 A+ grades in upper division physics courses and Matthew had 6, truly outstanding records. Both will be going to graduate school this September, and have bright futures ahead of them. Ethan will be working on his PH.D. in physics at UCLA, and Matthew will be at Stanford in the Applied Physics Ph.D. program.
Congratulations and best wishes to Ethan and Matthew!

Last modified: 07/10/2006

2006 Selma and Robert Silagi Award winner: Kevin A. McCarthy

news picture Kevin A. McCarthy, a senior who has worked hard to maintain a high standard of academic excellence in his classwork with a double major in Physics (BS) and Electrical Engineering (BS) at UCSD, has been named recipient of the 2006 Selma and Robert Silagi Award for undergraduate excellence in science by the Division of Physical Sciences at UCSD. An award luncheon held on June 1, 2006 at the UCSD Faculty Club honored McCarthy where he was presented with a $5,000 award by Dean Mark H. Thiemens on behalf of Laura J. Silagi from Venice, California. Laura Silagi, one of the surviving children of Selma and Robert Silagi, attended the luncheon.

Last modified: 06/14/2006

Professor Brian Keating receives an NSF Faculty Early Career Development Program Grant

news picture UCSD physics Professor Brian Keating has received an NSF Faculty Early Career Development Program (CAREER) Grant. Prof. Keating received the award for his proposal to measure the polarization of the cosmic microwave background (CMB) from the U.S. Amundsen-Scott South Pole Station over the next five years. The polarization of the CMB has the potential to constrain models of the very early universe including the period of cosmological inflation which is hypothesized to have produced a relict background of gravitational waves. To study the imprint of these gravitational waves on the CMB, Prof. Keating and his Caltech, JPL, UC-Berkeley and European collaborators developed a novel astronomical observatory called the Robinson Gravitational Wave Background Telescope/BICEP. This telescope uses 98 polarization sensitive bolometers operating at 0.25 Kelvin to measure fluctuations in the CMB to a precision of 100 nanoKelvin. Prof. Keating and UCSD graduate student Evan Bierman deployed BICEP to the South Pole in December 2005 and plan to operate the observatory and analyze its data over the next five years. More information on Prof. Keating's research is available at: http://physics.ucsd.edu/~bkeating

Last modified: 04/27/2006

Nanopore Method Could Revolutionize Genome Sequencing

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A team led by Physicist Massimiliano Di Ventra at the University of California, San Diego has shown the feasibility of a fast, inexpensive technique to sequence DNA as it passes through tiny pores. The advance brings personalized, genome-based medicine closer to reality.

Full Article

Last modified: 04/26/2006

Mayer Hall Addition Construction Begins

news picture Construction of the long-awaited Mayer Hall Addition is finally underway: the site has been fenced off, the contractor is on-site, and demolition started on January 30, 2006. The addition will house 45,000 assignable square feet of office, research laboratory, and teaching laboratory space, distributed over 5 floors. Construction of the addition is expected to last approximately 22 months (i.e., until October 2008); a further 14 months will be spent on the subsequent renovation of portions of the existing building. See site for more information:

Mayer Hall Addition Web Site

Last modified: 02/07/2006

Former UCSD Physicist Shares Descartes Award for Material that Reverses Light's Properties

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David R. Smith, a physicist formerly at the University of California, San Diego, has been awarded the European Union's Descartes Prize for Excellence in Scientific Research for developing at UCSD a new class of composite materials with unusual physical properties that scientists theorized might be possible, but had never before been able to produce in nature.

Complete story at http://ucsdnews.ucsd.edu/newsrel/science/mcdescartes.asp

Last modified: 12/16/2005

UCSD Professor of Physics Elected To National Academy Of Sciences

news picture The National Academy of Sciences today elected a biology professor and a physics professor at the University of California, San Diego to membership in the prestigious academy, one of the highest honors bestowed on U.S. scientists and engineers. M. Brian Maple, Bernd T. Matthias professor of physics and director of UCSD's Institute for Pure and Applied Physical Sciences, and Charles S. Zuker, a professor of biology and of neurosciences at UCSD, were among the 72 new members and 18 foreign associates from 13 countries elected to the academy this morning in recognition of their distinguished and continuing achievements in original research.

Their election brings the number of current faculty members at UCSD who are members of the National Academy of Sciences to 71, ranking the university seventh in the nation in the number of academy members. The National Academy of Sciences, established by Congress in 1863, serves as an official adviser to the federal government on matters of science and technology.

Mark Thiemens, Dean of UCSD's Division of Physical Sciences, and Eduardo Macagno, Dean of UCSD's Division of Biological Sciences, noted that The election of Professor Maple and Professor Zuker to the academy today is a testament to their scientific achievements and underscores the intellectual vitality of UCSD's two science divisions.

It's often said that Roger Revelle built this university from the top down by recruiting members of the National Academy of Sciences to UCSD. But much of our scientific talent, as demonstrated by the election today, resides in the faculty who have developed and established themselves at UCSD, added the two deans.

Maple received his doctorate in physics from UCSD in 1969, working under the renowned UCSD physicist Bernd Matthias, and was named Distinguished Alumnus of the Year at UCSD in 1987. An expert on high-temperature superconductors materials that lose all resistance to electricity at commercially attainable, cold temperatures he presided over the celebrated high-temperature superconductivity session, dubbed the Woodstock of Physics, during the American Physical Society's March meeting in 1987. His research interests also include magnetism, low-temperature physics, high-pressure physics and surface science. Maple has been on the faculty at UCSD since 1973.

Zuker, a 46-year-old neurobiologist, was born in Chile and moved to the U.S. to obtain his doctorate in molecular biology from the Massachusetts Institute of Technology. Zuker is also a Howard Hughes Medical Institute Investigator and has been on the faculty at UCSD since 1987. Recently elected to the Academy of Arts and Sciences, Zuker and his colleagues in his laboratory employ a combined molecular, genetic, and physiological approach to investigate the biology of sensory transduction mechanisms in photoreceptors, mechanoreceptors and taste receptors.

Attribution: Kim McDonaldhttp://ucsdnews.ucsd.edu/newsrel/science/mcnas.asp

Last modified: 12/16/2005

UCSD Physicists named to Smithsonian Magazine's 35 Innovators of Our Time

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Professors Margaret Burbidge and Sally Ride were named to Smithsonian Magazine's "35 Innovators of Our Time" in the November 2005 issue. The article marks the 35th anniversary of the magazine by "...revisiting scientists, artists and scholars who've enriched the magazine and our lives."

Article Summary
Margaret Burbidge By Marcia Bartusiak
Sally Ride By K.C. Cole

Last modified: 11/03/2005

UCSD Physics Graduate Student Wins Outstanding Dissertation Award

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Kenneth Burch, UCSD Physics student, has been chosen for a GMAG Outstanding Dissertation in Magnetism Award for 2006. The award consists of a cash prize, certificate and invited talk in an appropriate session at the 2006 March meeting in Baltimore.

More information can be found at: http://www.aps.org/units/gmag/

Last modified: 10/18/2005

2005 REU Physics of Sailing Trip

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Each year the Physics Department and its faculty host a number of undergraduates in its Research Experience for Undergraduates program. The students are selected from approximately 450 applicants. The program is funded by an NSF Grant (with Dmitri Basov and Hans Paar co-PIs).

Besides working hard in the labs and attending seminars and workshops, the students also take the Physics of Sailing course. The course consists of a classroom lecture and a laboratory component that takes place on the San Diego Bay in a 42' Catalina sailboat. The photograph shows the students, Charmaine Samahin and her husband Randy, and the instructor (Hans Paar).

Last modified: 09/14/2005

2005 UCSD Physics Ma and Malmberg Award Winners

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The Department of Physics is pleased to announce the winners of this year's Shang-keng Ma Memorial Award Endowed by the Shaoyeh Ma Foundation and Malmberg awards, our department's awards to the top undergraduate physics majors.

This years Ma award goes to Kyle Armour. Kyle is graduating with a GPA of ... ok, university regulations prohibit me from telling you. Let's just say its within epsilon of 4.0, where epsilon is a small number. Also, he garnered 10 A+ grades in physics courses! He has already done significant research in particle physics in Jim Branson's group, and is heading to graduate school at U. Washington where he intends to continue working in particle theory.

The Malmberg award goes to Tyson Kim. Tyson has distinguished himself in our biophysics program, and is the lead author on an applied physics letter (along with David Kleinfeld and Alex Groisman) that is soon to appear. Tyson has not yet decided between biophysics/MD-PhD programs at Harvard, U. San Francisco and UCSD. (We hope he chooses to stay in San Diego!)

Congratulations and best wishes to Tyson and Kyle!

Attribution: Dan Dubin - Vice Chair for Undergraduate Education

Last modified: 05/05/2005

UCSD Physics Graduate Student Earns DOE and NSF Award

news picture Chris Schroeder was selected in national competitions for the Computational Science Graduate Fellowship of the Department of Energy and the Graduate Research Fellowship of the National Science Foundation.

Both programs recognize and support outstanding graduate students in the relevant science, technology, and mathematics disciplines. Fellows are expected to become experts who can contribute significantly to research, teaching, and innovations in science and engineering. The CSGF recipients receive payments of all tuition and required fees for up to 4 years of study, a yearly stipend, matching funds for a computer workstation, a yearly academic allowance, and yearly conferences. Among the requirements and benefits are a plan of study which includes course work in Applied Mathematics, Science and Computer Science, and a practicum at a national DOE laboratory. NSF fellows receive tuition, fees, a yearly stipend for up to 3 years of study, with no requirement beyond annual reporting.






Last modified: 05/04/2005

Professor Mike Norman Named Fellow of American Academy of Arts and Sciences

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Five faculty members at the University of California, San Diego have been named fellows of the American Academy of Arts and Sciences, the academy has announced. The five are among 196 new fellows and 17 new foreign honorary members in the academy's 225th class.

The new fellows from UCSD are Jack Keil Wolf, professor of electrical and computer engineering at the Jacobs School of Engineering; Ajit P. Varki, professor of medicine and cellular and molecular medicine; Linda Preiss Rothschild and M. Salah Baouendi, professors of mathematics; and Michael L. Norman, professor of physics.

They join 76 current AAAS fellows on the UCSD faculty.

It gives me great pleasure to welcome these outstanding leaders in their fields, said Academy President Patricia Meyer Spacks. Fellows are selected through a highly competitive process that recognizes individuals who have made preeminent contributions to their disciplines and to society at large.

Fellows and members are nominated and elected by current members, comprising scholars and practitioners from mathematics, physics, biological sciences, humanities and the arts, public affairs and business. The academy will welcome this years fellows and honorary members at its annual induction ceremony on October 8 in Cambridge, Mass.

Full Article

Last modified: 04/28/2005

Nobel Laureate To Deliver Inaugural Physics Department Memorial Lecture In Honor of Prof. Norman Kroll

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Prof. David Gross, recipient of the 2004 Nobel Prize in Physics will speak on The Future of Physics in the inaugural lecture of the Physics Department Memorial Lecture series. This event will be held at 4:00 pm on Thursday, April 21 at the Liebow Auditorium in Basic Science Building.

This annual lecture series organized in the memory of Prof. Norman M. Kroll, a brilliant pioneer in Quantum physics and a founding member of the UCSD Physics department. During his forty year career at the UCSD, Professor Kroll made brilliant contributions to research in quantum electrodynamics, atomic physics, particle physics, free electron lasers and subatomic particle accelerators. He served as the chair of the physics department from 1963 to 1965 and from 1983 to 1988. A short description of Prof. Kroll's life is at http://ucsdnews.ucsd.edu/newsrel/science/mckroll.asp

This lecture series is generously supported by the financial contributions from the friends and family of Prof. Norman Kroll. The event is free and open to the public. Parking is $3.

David J. Gross is Director of the Kavli Institute for Theoretical Physics (KITP) and the first incumbent of the Frederick W. Gluck Chair in Theoretical Physics at the University of California at Santa Barbara. Professor Gross was awarded the 2004 Nobel Prize in Physics for solving, in 1973, the last great remaining problem of what has since come to be called the Standard Model of the quantum mechanical picture of reality and discovered along with his co-recipients how the nucleus of atoms works. This lecture is also a part of the worldwide celebration of 2005 as the year of physics.

Prof. David Gross


Last modified: 04/18/2005

CKM2005 International Workshop: CP Violation and The UnitarityTriangle

news picture The Physics department, in particular the Particle Physics group, is hosting the CKM2005 international workshop on "CP Violation and The Unitarity Triangle". More than 200 experts on the topic of matter-antimatter asymmetry from Asia, Europe and North America are attending this workshop which was inaugurated by Chancellor Fox on Tuesday. The workshop is being held at the Price center between March 15-18. The workshop details can be found at http://ckm2005.ucsd.edu/ A short summary of this workshop in layperson's terms is at http://ucsdnews.ucsd.edu/thisweek/2005/mar/03_14_antimatter.asp The plenary sessions of this workshop, held each morning, may be of interest to members of the physics department, particularly the graduate students. Admission is free for all affiliated with UCSD and we invite you to attend this workshop. We thank Chancellor Fox and Dean Theimens' office for their enthusiastic support and sponsorship of this workshop.

Last modified: 03/17/2005

Endgame for the Higgs Boson

news picture The last missing piece of scientists' fundamental model of particle physics is running out of places to hide. That piece, an elementary particle called the Higgs boson that is thought to give all matter mass, has evaded detection so far. But physicists working at the Large Hadron Collider (LHC) near Geneva, Switzerland, including a contingent of more than two dozen scientists from the University of California, San Diego, have ruled out most of the range of masses the Higgs could have, leaving just a narrow span where the elusive particle might be found. "If it exists, it has to be there. And if it's not there, it will be known to be science fiction by December," Vivek Sharma, a physics professor at UC San Diego told ScienceNOW. Sharma coordinates the international team searching for Higgs boson with the CMS detector, one of two large instruments deployed in the search. The other is called ATLAS. By speeding protons around a 27 kilometer ring at nearly the speed of light, then smashing them together, scientists fleetingly recreate conditions that prevailed when the universe began. In those moments the Higgs boson, if it exists, should pop into being and then quickly decay into other more familiar and recognizable particles, which CMS and ATLAS are poised to detect. In just five months of the LHC running, the two teams have eliminated -- at a 95 percent confidence level -- most of the range of possible masses the Higgs could have, Sharma reported at the biannual Lepton-Photon conference held recently in Mumbai. "The Higgs, if it exists, is now trapped between 114 and 145 GeV (Giga-electron volts, a measure of mass)," he said. A Higgs boson within that range would decay in predictable ways. The scientists have observed the kinds of sprays of particles they would expect to see from a Higgs boson, but not often enough to say the events aren't mere statistical fluctuations of well known background processes. A definitive interpretation will require more data, which the LHC is starting to deliver. Now back in operation after a pause that has allowed the team to ramp up the rate of collisions, the machine should deliver twice as much data as has accumulated so far by the end of October. "We are now entering a very exciting phase in the hunt for the Higgs boson," Sharma said. "If the Higgs boson exists between 114-145 GeV, we should start seeing statistically significant excesses over estimated backgrounds, and if it does not then we hope to rule it out over the entire mass range. One way or the other we are poised for a major discovery, likely by the end of this year."

Last modified: 10/11/2004

CTBP is hosting the 7th International Conference on Biological Physics

news picture World's leading Biological Physicists will gather from around the world for the International Conference on Biological Physics (ICBP2011) that will take place in La Jolla, California, June 19-24, 2011. The 7th ICBP meeting, a triennial IUPAP conference, comes at a time when biological physics is taking its place as a compelling frontier of research with rapidly growing interest in physical sciences departments worldwide.

The conference has a spectacular list of speakers including several Nobel laureates. The closing lecture will be given by the Secretary of Energy Steven Chu. ICBP2011 Local Organizing Committee includes CTBP and Physics Department faculty members Olga Dudko, Herbert Levine, Jose Onuchic and Christopher Smith.

More information is available at the conference website http:// icbp2011.ucsd.edu

Last modified: 10/11/2004

Former project scientist Quoc Nguyen innovates at start-up

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The Physics Department continues to drive the local San Diego economy through innovation. The latest example is NeurAccel, a La Jolla based start-up company that was founded by former Project Scientist Quoc Nguyen. NeurAccel offers a unique in vivo testing service for the efficacy of new pharmaceutical agents. The underlying technology was developed by Nguyen and then MD/PhD student Lee Schroeder in Prof. David Kleinfeld's laboratory* and is licensed to NeurAccel by UCSD. The continued advancement of this technology within the Department is funded by a grant from the National Institute of Drug Abuse to Kleinfeld and his colleague Prof. Paul Slesinger at the Salk Institute.

*An in vivo biosensor for neurotransmitter release and in situ receptor activity. Q.-T. Nguyen*, L. F. Schroeder*, M. Mank, A. Muller, P. W. Taylor, O. Griesbeck and D. Kleinfeld, Nature Neuroscience (2010) 13:127-132.

Union Tribune Article: http://web.signonsandiego.com/news/2011/sep/05/window-into-the-brain/?ap

Last modified: 10/11/2004

Like Superman's X-Ray Vision, New Microscope Reveals Nanoscale Details

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Physicists at UC San Diego have developed a new kind of X-ray microscope that can penetrate deep within materials like Superman's fabled X-ray vision and see minute details at the scale of a single nanometer, or one billionth of a meter.

But that is not all. What’s unusual about this new, nanoscale, X-ray microscope is that the images are not produced by a lens, but by means of a powerful computer program.

The scientists report in a paper published in this week’s early online edition of the Proceedings of the National Academy of Sciences that this computer program, or algorithm, is able to convert the diffraction patterns produced by the X-rays bouncing off the nanoscale structures into resolvable images.

“The mathematics behind this is somewhat complicated,” said Oleg Shpyrko, an assistant professor of physics at UC San Diego who headed the research team. “But what we did is to show that for the first time that we can image magnetic domains with nanometer precision. In other words, we can see magnetic structure at the nanoscale level without using any lenses.”

Magnetic domains appear like the repeating swirls of fingerprint ridges. As the spaces between the domains get smaller, computer engineers can store more data.. Credit: UC San Diego

One immediate application of this lens-less X-ray microscope is the development of smaller, data storage devices for computers that can hold more memory.

“This will aid research in hard disk drives where the magnetic bits of data on the surface of the disk are currently only 15 nanometers in size,” said Eric Fullerton, a co-author of the paper and director of UC San Diego’s Center for Magnetic Recording Research. “This new ability to directly image the bits will be invaluable as we push to store even more data in the future.”

The development should be also immediately applicable to other areas of nanoscience and nanotechnology.

“To advance nanoscience and nanotechnology, we have to be able to understand how materials behave at the nanoscale,” said Shpyrko. “We want to be able to make materials in a controlled fashion to build magnetic devices for data storage or, in biology or chemistry, to be able to manipulate matter at nanoscale. And in order to do that we have to be able to see at nanoscale. This technique allows you to do that. It allows you to look into materials with X-rays and see details at the nanoscale.”

“Because there is no lens in the way, putting a bulky magnet around the sample or adding equipment to change the sample environment in some other way during the measurement is much easier with this method than if we had to use a lens,” Shpyrko added.

Ashish Tripathi, a graduate student in Shpyrko’s lab, developed the algorithm that served as the X-ray microscope’s lens. It worked, in principle, somewhat like the computer program that sharpened the Hubble Space Telescope’s initially blurred images, which was caused by a spherical aberration in the telescope’s mirror before the telescope was repaired in space. A similar concept is employed by astronomers working in ground-based telescopes who use adaptive optics, movable mirrors controlled by computers, to take out the distortions in their images from the twinkling star light moving through the atmosphere.

But the technique Tripathi developed was entirely new. “There was a lot of simulation involved in the development; it was a lot of work,” said Shpyrko.

To test their microscope’s ability to penetrate and resolve details at the nanoscale, the physicists made a layered film composed of the elements gadolinium and iron. Such films are now being studied in the information technology industry to develop higher capacity, smaller, and faster computer memory and disk drives.

“Both are magnetic materials and if you combine them in a structure it turns out they spontaneously form nanoscale magnetic domains,” Shpyrko. “They actually self assemble into magnetic stripes.”

Under the X-ray microscope, the layered gadolinium and iron film looks something like baklava dessert that crinkles up magnetically to form a series of magnetic domains, which appear like the repeating swirls of the ridges in fingerprints. Being able to resolve those domains at the nanoscale for the first time is critically important for computer engineers seeking to cram more data into smaller and smaller hard drives.

As materials are made with smaller and smaller magnetic domains, or thinner and thinner fingerprint patterns, more data can be stored in a smaller space within a material. “The way we’re able to do that is to shrink the size of the magnetic bits,” Shpyrko said.

The technique should find many other uses outside computer engineering as well.

“By tuning the X-ray energy, we can also use the technique to look at different elements within materials, which is very important in chemistry,” he added. “In biology, it can be used to image viruses, cells and different kinds of tissues with a spatial resolution that is better than resolution available using visible light.”

The scientists used the Advanced Photon Source, the most brilliant source of coherent X-rays in the Western Hemisphere, at the University of Chicago’s Argonne National Laboratory near Chicago to conduct their research project, which was funded by the U.S. Department of Energy. In addition to Tripathi, Shpyrko and Fullerton, a professor of electrical and computer engineering at UC San Diego, other co-authors of the paper include UC San Diego physics graduate students Jyoti Mohanty, Sebastian Dietze and Erik Shipton as well as physicists Ian McNulty and SangSoo Kim at Argonne National Laboratory.


Media Contact: Kim McDonald (858) 534-7572, kmcdonald@ucsd.edu

Comment: Oleg Shpyrko (858) 534-3066, oshpyrko@ucsd.edu

Last modified: 10/11/2004

In Memoriam: Dr. Norman Kroll

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We regret to inform you that our colleague Norman Kroll passed away on Sunday, August 8, 2004. One of UCSD's founding faculty, Norman was a member of the Department of Physics and one of its most distinquished emeriti. He was a brilliant theoretical physicist with deep physical insight and broad scientific interests.

He took an active interest in the Physics Department and served as Department Chair for two terms (1963-66 and 1983-1989). We will miss Norman's keen intellect and wise counsel. The Department will keep you informed of the wishes of Norman's family regarding his memorial.

Prof. Kroll was born in 1922 and was appointed professor in 1962.

Pictures from Norman's 80th Birthday Celebration are available at: Norman Kroll 80th Birthday Celebration

Last modified: 08/12/2004

UCSD Professor of Physics Elected To National Academy Of Sciences

news picture The National Academy of Sciences today elected a biology professor and a physics professor at the University of California, San Diego to membership in the prestigious academy, one of the highest honors bestowed on U.S. scientists and engineers.

M. Brian Maple, Bernd T. Matthias professor of physics and director of UCSD's Institute for Pure and Applied Physical Sciences, and Charles S. Zuker, a professor of biology and of neurosciences at UCSD, were among the 72 new members and 18 foreign associates from 13 countries elected to the academy this morning in recognition of their distinguished and continuing achievements in original research.

Their election brings the number of current faculty members at UCSD who are members of the National Academy of Sciences to 71, ranking the university seventh in the nation in the number of academy members. The National Academy of Sciences, established by Congress in 1863, serves as an official adviser to the federal government on matters of science and technology.

Mark Thiemens, Dean of UCSD's Division of Physical Sciences, and Eduardo Macagno, Dean of UCSD's Division of Biological Sciences, noted that The election of Professor Maple and Professor Zuker to the academy today is a testament to their scientific achievements and underscores the intellectual vitality of UCSD's two science divisions.

It's often said that Roger Revelle built this university from the top down by recruiting members of the National Academy of Sciences to UCSD. But much of our scientific talent, as demonstrated by the election today, resides in the faculty who have developed and established themselves at UCSD, added the two deans.

Maple received his doctorate in physics from UCSD in 1969, working under the renowned UCSD physicist Bernd Matthias, and was named Distinguished Alumnus of the Year at UCSD in 1987. An expert on high-temperature superconductors materials that lose all resistance to electricity at commercially attainable, cold temperatures he presided over the celebrated high-temperature superconductivity session, dubbed the Woodstock of Physics, during the American Physical Society's March meeting in 1987. His research interests also include magnetism, low-temperature physics, high-pressure physics and surface science. Maple has been on the faculty at UCSD since 1973.

Zuker, a 46-year-old neurobiologist, was born in Chile and moved to the U.S. to obtain his doctorate in molecular biology from the Massachusetts Institute of Technology. Zuker is also a Howard Hughes Medical Institute Investigator and has been on the faculty at UCSD since 1987. Recently elected to the Academy of Arts and Sciences, Zuker and his colleagues in his laboratory employ a combined molecular, genetic, and physiological approach to investigate the biology of sensory transduction mechanisms in photoreceptors, mechanoreceptors and taste receptors.

Attribution: Kim McDonaldhttp://ucsdnews.ucsd.edu/newsrel/science/mcnas.asp

Last modified: 05/20/2004